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JANUARY  10, 1979 



ISSN  (K)28-i:544 

Vol.  93 


A  quarterly 

devoted  to 

malacology  and 

the  interests  of 


Founded  1889  bv  Henry  A.  Pilsbry.  Continued  by  H.  Burrington  Baker. 
Editor-in-Chief;  R.  Tucker  Abbott 



Dr.  Arthur  H.  Qarke,  Jr. 
Division  of  Mollusks 
National  Museum  of  Natural  History 
Washington,  D.C.  20560 

Dr.  William  J.  Clench 
Curator  Emeritus 
Museum  of  Comparative  Zoology 
Cambridge,  Mass.  02138 

Dr.  William  K.  Einerson 
Department  of  Living  Invertebrates 
The  American  Museum  of  Natural  History 
New  York,  New  York  10024 

Mr.  Morris  K.  Jacobson 
Department  of  Living  Invertebrates 
The  American  Museum  of  Natural  History 
New  York,  New  York  10024 

Dr.  Aurele  La  Rocque 
Department  of  Geology 
The  Ohio  State  University 
Columbus,  Ohio  43210 

Dr.  James  H.  McLean 
Los  Angeles  County  Museum  of  Natural  History 
900  Exposition  Boulevard 
Los  Angeles,  California  90007 

Dr.  Arthur  S.  Merrill 
Woods  Hole  Biological  Laboratory 
National  Marine  Fisheries  Service 
W(X)ds  Hole,  Massachusetts  02543 

Dr.  Donald  R.  Moore 
Division  of  Marine  Geology 
School  of  Marine  and  Atmospheric  Science 
10  Rickenbacker  Causeway 
Miami.  Florida  33149 

Dr.  Joseph  Rosewater 
Division  of  Mollusks 
U.  S.  National  Museum 
Washington,  D.C.  20560 

Dr.  G.  Alan  Solem 

Department  of  Invertebrates 
Field  Museum  of  Natural  History 
Chicago,  Illinois  60605 

Dr.  David  H.  Stansbery 
Museum  of  Zoology 
The  Ohio  State  University 
Columbus,  Ohio  43210 

Dr.  Ruth  D.  Turner 
Department  of  Mollusks 
Museum  of  Comparative  Zoology 
Cambridge,  Mass.  02138 

Dr.  Gilbert  L.  Voss 
Division  of  Biology 

School  of  Marine  and  Atmospheric  Science 
10  Rickenbacker  Causeway 
Miami,  Florida  33149 

Dr.  Charies  B.  Wurtz 
3220  Penn  Street 
Philadelphia,  Pennsylvania  19129 


Dr.  R.  Tucker  Abbott 
American  Malacologists,  Inc. 
Box  4208,  Greenville,  Delaware  19807 

Mrs.  Horace  B.  Baker 
Business  and  Subscription  Manager 
11  Chelten  Road 
Havertown,  Pennsylvania  19083 

The  Nautilus  (USPS  374-980) 
ISSN  fK)28-1344 
American  Malacologists,  Inc. 
429  B  Arthur  Drive.  Hockessin,  Delaware 
Mail:  Box  4208,  Greenville,  Delaware  19807 

Second  Class  Postage  paid  at  Hockessin,  Delaware 

Subscription  Price:  $9.00  (see  inside  back  cover) 
$10.00  (foreign) 



Volume  93,  number  1  —  January  10, 1979 

ISSN  0028-1344 


William  K.  Emerson  and  Anthony  D'Attilio 

Six  New  Living  Species  of  Muricacean  Gastropods 1 

William  K.  Emerson  and  William  E.  Old,  Jr. 

Scaphella  contoyensis,  a  New  Volutid  (Gastropoda)  from  East  Mexico 10 

W.  Stephen  Thomas 

A  Biography  of  Andrew  Garrett,  Early  Naturalist  of  Polynesia:  Part  1 15 

Douglas  S.  Jones 

The  Nemertean,  Malacohdella  grossa,  in  the  Ocean  Qushog,  Arctica  islandica  (Bivalvia) 29 

Gary  L.  Pace,  Ernest  J.  Szuch  and  Richard  W.  Dapson 

Depth  Distribution  of  Three  Gastropods  in  New  Mission  Bay,  Lake  Michigan 31 

Dorothy  Blanchard  and  Lowell  L.  Getz 

Arion  subfuscus  in  Southeastern  Michigan 36 

David  Pool  and  Jack  McCullough 

The  Asiatic  Clam,  Corbicula  manilensis,  from  Two  Reservoirs  in  Eastern  Texas 37 

J.  Roy  Robertson 

Evidence  for  Tidally  Correlated  Feeding  Rhythms  in  the  Eastern  Mud  Snail,  Ilyanassa  obsoleta  ....    38 

Edward  B.  Hatfield 

Food  Sources  for  Anachis  avara  (Columbellidae)  and  a  Discussion  of  Feeding  in  the  Family   40 

Jean  Ann  Nichols  and  J.  Roy  Robertson 

Field  Evidence  that  the  Eastern  Mud  Snail,  Ryanassa  obsoleta.  Influences  Nematode  Community 
Structure    44 

Publications  Received ii       News ii 


Will  pay  good  prices  for  libraries   second-  302--239-2025)  or  write:   R.  Tucker  Abbott, 

hand  books  and  reprmts  on  mollusks,  shells  Amencnn  Mahwohgist,.  Inc..  P.  0.  Box  4208. 

and  conchology.  Back  numbers  of  The  NauU-  Greenville.  DE  19807.  Free  appraisals. 
lus.  vols.  40-71  wanted,  $1.50  each.  Phone  (1- 


Houbrick,  Richard.  S.  1978  (Dec.  15).  The  Family  Centhiidae 
in  the  Indo-Pacific.  Part  1:  The  Genera  Rhuuirlnri.% 
Pseudovertagus  and  Clavocerithium.  Monographs  of  Marine 
Motlmca.  No.  1.  pp.  1-130.  98  pis.  3  in  color.  Taxonomic 
revision,  biologj'.  anatomy,  phylogeny  and  geographical 
distribution  of  47  living  and  fossil  species.  American 
Malacologists.  Inc.  $17..50,  postage  paid. 

Chatfield.  .June  E.  1978.  Welsh  Sea-fhells.  44  pp..  90  figs.  (20  in 
color.  Paperback.  National  Maseum  of  Wales.  Cathays  Park. 
Cardiff.  U.K.  CFl  3NP.  Remit  U.S.  $.3.00 or  jC  1..50 sterling.  An 
e.xcellent  little  guide  with  90  common  shore  species. 

Goryachen.  V.  N.  1978.  Gastropod  Mollusks  of  the  genus  Sep- 
tunea  Rciding  of  the  Bering  Sea.  90  pp..  25  pis.  Science 
Press,  Moscow  (in  Russian). 

The  Pariah,  no.  4.  Sept.  1978.  Edited  by  Jerr>'  C.  Walls.  8  pp. 
Contains  review  of  Harpidae  (.J.  G.  Walls),  note  on  Cin>raea 
thoninsi  (P.  W.  Clover)  and  remarks  on  Conns  patae  (J.  G. 
Walls).  Available  for  50  cents.  P.O.  Box  42.  Hightstown.  N.J. 

Popenoe.  W.  P.  and  R.  M.  Kleinpell.  1978.  Age  and 
Stratigraphic  Significance  fur  Lyellian  Correlation  of  the 
Fauna  of  the  Vigo  Formation.  Luzon.  Philippines.  Occ. 
Papers  California  Acad.  Sci..  no.  129.  pp.  1-173.  18  pis..  1 

Saul.  Louella  R.  1978.  The  North  Pacific  Cretaceous  Trigoniid 
Genus  Yaadia.  Univ.  Calif.  Publ.  in  Geol.  Sci..  vol.  119:  1-65, 
12  pis.  $7.25.  Excellent  account. 

Zhengzhi.  Dcjug.  1976.  On  Three  New  Species  of  the  Genus  Oc- 
topus from  the  Chinese  Waters.  Studia  Marina  Sinica,  no. 
11.  pp.  211-215.  (0.  nanhaiensis,  0.  striolatus  and  0. 
yuanydongensis  new  species). 

Zhengzhi.  Doug.  1978.  On  the  Geographical  Distribution  of  the 
Cephalopods  in  the  Chinese  Waters.  Oceanologia  et  Lim- 
nologia Sinica.  vol.  9,  no.  1.  pp.  108-116. 

Wu,  Shi-Kuei  and  Nancy  Brandauer.  1978.  Natural  History 
Inventory  of  CoUirado.  2.  The  Bivalvia  of  Colorado.  Univ. 
Colorado  Museum.  Boulder.  CO  80.309. 60  pp.  87  figs.,  keys. 

Giese,  Arthur  C.  and  John  S.  Pease,  (editors).  1977.  Reproduc- 
tion of  Marine  Invertebrates.  Vol.  4.  Molluscs:  Gastropods 
and  Cephalopods.  369  pp.  Academic  Press.  HI  Fifth  Ave.. 
N.Y..  NY  10003.  Hardback.  .$38.00.  An  excellent,  well- 
illustrated  and  w^ell-documented  account  by  competent 
workers-  Includes  recent  reviews  of  reproduction  on  Pro- 
sobranchia  (H.  H.  Webber).  Opisthobranchia  (R.  D. 
Beeman);  estuarine  Basommatophora  (A.  J.  Berry); 
Nautilus  (Norine  Haven);  Squids  (J.  M.  Arnold  and  L  D. 
Williams-.^mold):  and  Octopoda  (M.  J.  and  J.  Wells). 


A.M.r.  -  W.S.M.. Joint  Mpptiivj 
Symposium  on  the  Life  Histories  of  Mollusks 

Papers  on  any  aspect  of  molluscan  life  histories 
will  be  considered  for  presentation  at  a  sym- 
posium to  be  held  during  the  joint  meeting  of  the 
Western  Society  of  Malacologists  and  the  Amer- 
ican Malacological  Union  in  Corpus  Christi, 
Texas,  5-11  August  1979.  Presentations  should 
be  concerned  with  an  aspect  of  the  reproduction, 
development,  growth,  or  population  dynamics  of 
mollusks.  Theoretical  papers  on  the  evolution  of 
life  history  traits  of  mollusks  are  also  invited. 
Opportunity  for  publication  of  abstracts  or  full 
length  versions  of  papers  pre.sented  at  the  sym- 
posium will  be  provided.  Further  information 
and  a  Call  for  Papers  is  available  from: 

David  R.  Lindberg 

Invertebrate  Zoology 

California  Academy  of  Sciences 

Crt)lden  Gate  Park 

San  Francisco,  CA  94 118 


The  international  society  of  professional 
malacologists  (formerly  the  Unitas  Malacologica 
Europaea)  is  now  open  to  all  scientists  interested 
in  living  or  fossil  mollusks.  The  President  is  Dr. 
Jean  M.  Gaillard.  Museum  d'Histoire  Naturelle, 
55  rue  de  Buffon,  F-75005  Paris,  France,  to  whom 
readers  should  write  concerning  the  next  and 
Seventh  International  Malacological  Congress. 
Tliese  meetings  will  be  held  August  31  (registra- 
tion) to  September  6,  1980,  on  the  Mediterranean 
coast  of  France  near  the  "Laboratoire  Arago". 
Secretary  of  the  Unitas  Malacologica  is  Dr. 
Oliver  E.  Paget,  Naturhistorisches  Museum, 
Burgring  7,  A-1014  Vienna,  Austria. 

Vol.  93(1)  Januaty  lU,  1979  THE  NAUTILUS        1 


William  K.  Emerson 

American  Museum  of  Natural  History 
New  York,  N.  Y.  10024 


Anthony  D'Attilio 

Natural  History  Museum 
San  Diego,  California  90112 


The  following  neiv  species  of  gastropods  referable  to  the  Muricidae  are 
described:  Pteropurpura  benderskyi  from  West  Afiica:  Favartia  guamensis  and  F. 
dorothyae//'o»(  the  western  Pacific,  and  F.  elatensis/n*m  the  Red  Sea:  Murexiella 
mactanensis  from  the  we^em  Pacific;  and  Siphonochelus  radwini  from  the 
western  Atlantic.  A  recently  described  species.  Murexiella  martini  Shikama,  1977, 
from  the  western  Pacific,  is  illustrated  and  a  supplementary  description  is  given. 
Dermomurex  neglecta  (Habe  and  Kosuge,  1971),  from  the  western  Pacific,  is  il- 
hi.sf  rated  and  a  tran.slation  of  the  original  description  is  provided. 

At  the  time  George  E.  Radwin  and  the  junior 
author  were  preparing  the  text  for  "Murex  Shells 
of  the  World,  An  Illustrated  Guide  to  the 
Muricidae"  (Radwin  and  D'Attilio,  1976),  a 
number  of  taxa  were  recognized  by  them  as  new 
species.  Fifteen  of  these  species  were  described  in 
an  appendix  to  their  book.  Although  they  in- 
tended to  describe  elsewhere  several  other  taxa 
that  were  received  after  the  text  of  the  book  was 
completed  in  mid-1971,  the  tragic  and  untimely 
death  of  Dr.  Radwin  in  1977  terminated  their 
joint  venture. 

At  the  request  of  the  junior  author,  the  senior 
author  has  joined  him  in  the  preparation  of  the 
present  report,  which  was  based  in  part  on 
preliminary  notes  prepared  jointly  by  D'Attilio 
and  Radwin  for  two  of  the  taxa  described  herein. 
The  new  taxa  are  classified  largely  according  to 
the  system  followed  by  Radwin  and  D'Attilio 


We  are  grateful  to  the  following  collectors  for 
the  loan  and/or  donation  of  specimens:  Israel 
Bendersky,  L.  J.  Bibbey,  Albert  E.  Deynzer, 
Francis  Fernandez,  Dorothy  and  Robert 
Janowsky,  Leo  Kempczenski,  Don  Pisor,  and 
Eugenia  Wright.  Dr.  Joseph  Rosewater  of  the 
Department  of  Invertebrate  Zoologv',  National 
Museum  of  Natural  History,  Smithsonian  Institu- 
tion and  Dr.  H.  K.  Mienis  of  the  Zoological 
Museum,  Hebrew  University  of  Jerusalem  lent 

additional  material.  Dr.  Emily  H.  Yokes  of  the 
Department  of  Geology,  Tulane  University,  pro- 
vided data  and  the  photographs  used  to  illustrate 
figures  17  and  18.  Masao  Tabakotani  of  Bronx- 
ville.  New  York,  generously  contributed  a 
translation  of  Japanese  te.xt.  William  E.  Old,  Jr. 
and  G.  Robert  Adlington  of  the  American 
Museum  of  Natural  History  kindly  provided 
respectively,  technical  assistance  and  the 


AMNH  =  American  Museum  of  Natural  History, 

New  York,  New  York 
HUJ  =Zoological  Museum.  Hebrew  University  of 

Jerusalem,  Israel 
NMNH  =  National  Museum  of  Natural  History, 

Washington,  D.C. 
SDMNH    =San    Diego    Museum    of   Natural 

History,  San  Diego,  California 

Family  Muricidae 

Subfamily  Muricinae 

Genus  Deimomurex  Monterosato,  1890 

Type    species:    Murex    scalarinus    Bivona-Bemardi ,    1832 

( =  M.  xcalaroides  Blainville,  1829),  by  original  designation. 

Dermomurex  neglecta  (Habe  and  Kosuge,  1971) 

Figs.  17. 1,^ 

"Description:  Shell  distinguished  by  its  varices, 
five  in  number,  in  each  whorl.  They  are  broad 
and    somewhat    prosocline    at    the    shoulder    to 

2       THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

suture  position.  Whorls  between  varices  are 
sculptured  by  numerous  fine  spiral  striae  so  that 
it  looks  almost  smooth.  Siphonal  fasciole  is 
outstanding  and  umbilicus  is  open.  Shell  white 
with  slight  yellowish  tinge  in  color." 

"This  species  is  distinguished  for  the  shape  and 
varices.  Actually  two  specimens  are  known,  both 
caught  in  South  China  Sea  and  brought  back  to 
the  port  of  Kaohsiung,  Taiwan."  (Translation  of 
the  Japanese  text,  courtesy  of  M.  Tabakotani .) 

Meaaurementu:  Holotype,  length  22.5  mm, 
width  11.2  mm;  specimen  illustrated  herein, 
length  20  mm,  width  ll.(X)  mm.  (Wright  collec- 

Type  locality:  "South  China  Sea",  fide  Habe 
and  Kosuge  (1971,  page  7).  Here  restricted  to  off 
Bohol  Island,  Philippines. 

Material  examined:  1  specimen,  off  Balicason, 
Bohol  Island,  Philippines,  in  366  meters,  Eugenia 
Wi'ight  collection. 

Remarks:  At  the  suggestion  of  Dr.  Emily  H. 
Yokes,  we  have  presented  here  a  translation  of 
the  description  of  this  poorly  known  western 
Pacific  taxon,  together  with  photographs  of  a 
specimen  from  the  Philippines  (figures  17,  18), 
which  along  with  another  one,  had  been  sent  to 
her  for  identification.  Although  this  species  was 
originally  described  as  Phyllocoma  neylecta  by 
Habe  and  Kosuge  (1971,  p.  7,  text  figure),  it  is 
referable  to  the  genus  Dermomurex  and  is  the 
first  Recent  record  of  the  genus  (sennu  i^trirto)  in 
the  Indo-Pacific.  Yokes  (1975,  p.  129)  cited  this 
record  based  on  the  Philippine  specimens  which 
were  thought  to  represent  an  undescribed  species. 
She  pointed  out  (1975,  op.  cit.)  that  the  specimens 
lack  apertural  denticulations  on  the  outer  lip,  in 
contrast  to  the  previously  known  representatives 
of  Dermomurex  (i^emu  stricto).  According  to  Dr. 
Yokes  (in  litt.)  the  present  species  is  a  probable 
descendent  of  Dermomurex  arutirostatii^  (Wanner 
and  Hahn,  1935,  p.  254,  pi.  19,  figs.  8-10)  from  the 
Miocene  of  Java. 

Subfamily  Ocenebrinae 
Genus  Pteropurpura  Joussenume,  1880 
Type  species:  Murex  macroptents  Deshayes,  1839,  by  original 

Pteropurpura  benderskyi,  n.  sp. 

Figs.  1.2.19 

Des^ciiptioii:  Shell  small  for  genus,  attaining  23 
mm.  in  length,  trigonally  fusiform  in  appearance. 
Spire  acute  and  high,  with  l'/2  polished,  brown 
nuclear  whorls,  followed  by  5  convex,  postnuclear 
whorls;  suture  distinct,  not  strongly  impressed. 
Body  whorl  moderate  in  size.  Aperture  ovate, 
with  peristome  entire  and  mostly  erect,  except 
for  the  posterior  portion  of  left  side  in  the 
parietal  region.  Siphonal  canal  broad,  sealed  (ex- 
cept at  the  recurved,  tapering  distal  end), 
moderate  in  length  and  accommodating  the  siphon- 
al fasciole.  Body  whorl  with  three  winged  varices; 
each  varix  with  webbing  between  prominent 
spine-points.  A  medial  costate  ridge  and  two  less 
prominent  flanking  costae  intervene  between 
each  pair  of  consecutive  varices.  Spiral  sculpture 
of  numerous  primary  and  secondary  cords  ex- 
tending over  body  and  siphonal  canal.  Primary 
cords  strongest  on  dorsal  surfaces  of  the  spines. 
Spine  at  shoulder  margin  longest;  body  with  a 
less  prominent  spine  medially  placed  and  with  a 
minor  spine  at  the  base  of  body  whorl  and  on  the 
upper  portion  of  siphonal  canal.  Leading,  or  ven- 
tral sides,  of  varical  spines  weakly  open;  last 
varix  with  leading  edge  sculptured  with  fine,  low 
undulating  lamellae  and  with  some  grovrth  lines 
raised  at  intervals  to  give  a  somewhat  scabrous 
texture  to  the  surface.  Shell  tan  to  dark-brown, 
paler  on  the  varical  surfaces;  aperture  off-white 
and  porcelaneous.  Operculum:  The  morphology  is 
typically  ocenebrinean,  as  described  by  Radwin 
andD'Attilio(1976,p.  111). 

Radula:  Radular  dentition  is  similar  in  morph- 
ological characters  to  those  of  the  type  species  of 
Pteropurpura,  P.  macroptera  (Deshayes,  1839); 
consult  the  radular  illustrations  of  the  Deshayes' 
taxon  (Rjidwin  and  D'Attilio,  1976,  p.  131,  fig.  81) 
with  the  basal  and  frontal  views  of  a  rachidian 
and  a  frontal  view  of  a  lateral  tooth  of  the  pre- 
sent species  (figure  19  herein). 

Measurements:  Holotype,  length  23  mm,  width, 
including  varices  13.9  mm;  smallest  paratype  (SD 
MNH  no.  72626).  17.7  mm  in  length. 

FIGS.  1  and  2,  Pteropurpura  bendersl<yi  n.  up.,  holotmw.  AMNH  lK.iHl9.  X.l  3  and  4,  Favartia  dorothyae  n.  sp..  holotype.  AMNH 
183821.  X.l.  5  and  6,  Favartia  rosea  Hahe.  1.961.  .Janowsky  CDllection.  tmirled  in  Kii  Channel.  Wnkayama  Prefecture.  .Japan,  in  U6 
meters.  X.l.  7  mid  8,  Favartia  mactanensis  n.  sp..  holotype.  AMNH  1871H6.  X.l.  9  and  10,  Murexiella  martini  Shikama,  1977,  SDMNH 
72627,  Bohol  Islattd,  Philippines,  X2.  (Stated  enlargements  are  an  appronmalion) 

Vol.  93(1) 

January  10. 1979 

THE  NAUTILUS       3 



*  ■'/ 


















January  10, 1979 

Vol.  93(1) 

Tif})c  lornlity:  Off  Luanda,  Angola,  Africa, 
dredged  in  5<l  meters,  sandy  bottom,  July  15,  1977, 
FYancis  Fernandez  collector. 

Material  examined:  Holotype  AMNH  183819, 
from  type  locality,  1  paratype  SDMNH  72626,  ex 
Bendersky  collection,  and  1  paratype,  Janowsky 
collection,  hnjth  from  off  Luanda,  Angola,  dredged 
in  80  meters,  February  10,  1977. 

Remarks:  Until  the  discovery  of  this  new- 
species,  only  one  living  representative  of  this 
genus  was  knovra  to  occur  in  the  Atlantic  Ocean. 
Ihe  other  living  Pteropurpura  are  found  in  the 
northern  Pacific,  with  three  in  northwestern 
waters  (largely  off  southeastern  Japan)  and  with 
five  in  northeastern  waters  off  California  and 
northwestern  Me.xico  (see  Radwin  and  D'Attilio, 
1976,  pp.  129  to  133).  The  present  species  (figures 

1.  2)  differs  from  P.  bequaeni  (Clench  and  Pe'rez 
Farfante,  pi.  21,  figs.  1,  2,  1945),  which  ranges 
from  North  Carolina  to  the  Dry  Tortugas,  in 
several  characteristics  (see  comparative  data  in 
table  1).  The  two  taxa  clearly  represent  twin 
species,  or  cognates,  separated  by  the  present  ex- 
panse of  deep  water  of  the  Atlantic  Basin. 

Subfamily  Muricopsinae 
Genus  Faimiia  Jousseaume,  1880 
Type  species:  Murei  breinculus  Sowerby.  18.34.  by  nripinal 

Favartia  guatnensis  n.  .sp. 
Fips.  11.12 

Drxcription:  Shell   small,  attaining  8  mm   in 
length,  fusiform.  Characterized  by  strong  rugose 

FIGS.  11  (!/»/  12,  Favartia  guamensi.s  n.  up.,  halnti/pe.  SDMXII  ;av.5.    X.r  l.S  ami  14,  Favartia  elatensis  >i.  sp..  pamtifpe. 
SDMNH  6M5ia.   X.5.  15  and  16,  Favartia  dorothyae  n.  .fp..  parati/pc-  AMNH  lS^i82:i.   X.i.  17  and  18,  Dermomurex  neglecta 

(Hahe  and  Koxntir.  1!)7II:  Wnnht  culU'ctiiDi.  (iffBulml  Island.  Philippines.  XJ.  (Stated  rnlniyrnii-nts  art' an  apprariniatitin) 

Vol.  93(1) 

January  10, 1979 


TABLE  1.  Comparative  diagnostic  charm-ters  of  Pteropurpura  bequaerti  and  Pt.  benderskyi 

Pteropurpura  bequaerti 

Maximum  size  42  mm 

Numbers  of  whorls  6  to  7 

Outer  lip  crenulated 

Varices  blade-like 

Axial  sculpture  a  single,  low  knob 

Spiral  sculpture  terminates  in  toothlike  points  on  varical 


Color  gray-white;  tip  of  siphonal  canal  suffused 

with  purple-brown. 

sculpture.  Protoconch  low,  smooth  with  IVz 
whorls;  followed  by  5  convex  whorls;  suture  deep 
but  obscured  at  varices;  spire  well  elevated. 
Aperture  ovate;  peristome  weakly  erect;  anal 
sulcus  deep,  constricted  in  front  into  a  closed 
channel.  Siphonal  canal  with  rostrate  fasciole, 
broader  above,  tapering  distally,  slightly  recurved 
with  a  narrow  sinuous  opening.  Shell  with  5 
strong,  spiral  cords,  squarish  in  cross-section  and 
with  an  additional  cord  on  the  canal;  cords 
crossed  by  strongly  elevated  fimbriae;  fimbria- 
tions  extend  into  the  interspaces.  Spiral  cords 
with  a  strong  central  groove,  crossed  by  fine 
lines,  and  with  fimbriae  forming  strong,  canopy- 
like scales;  scales  further  interrupted  axially  by  5 
to  8  fine  grooves;  scales  scalloped  on  terminal 
edge.  Varical  flanges  elevated  and  terminally 
wavy;  early  whorls  with  6  varices;  body  whorl 
with  4  varices.  Color  of  shell  deep  orange-red, 
ranging  to  yellow  in  the  four  specimens  ex- 

Measurements:  Holotype,  7.5  mm  in  length; 
largest  paratype,  7.7  mm  in  length;  smallest 
paratype,  6.6  mm  (Pisor  collection). 

Type  locality:  Off  Orote  Cliffs,  Guam,  Marianas 
Islands,  in  18  to  21  meters  under  large  boulders, 
5-1-1977,  Leo  Kempczenski  collector. 

Material  examined:  Holotype,  SDMNH  no. 
72625;  1  paratype,  Leo  Kempczenski  collection 
and  1  paratype,  AMNH  no.  183820,  all  collected 
by  Leo  Kempczenski  from  type  locality;  1 
paratype  from  type  locality,  Don  Pisor  collection; 

Pt.  benderskyi.  n.  sp. 

23  mm 

5  (or  more  ?) 

not  noticeably  crenulated 

spine-like  projections 

medial  costae  and  2  less  prominent  flanking  costae. 

varical  margins  extended  into  4  broad-based,  spiny 
terminations,  with  scabrous  lamellae  on  ventral  sur- 

tan  to  dark-brown,  paler  on  ventral  surface 

1  paratype  from  coral  rubble,  in  18  meters,  SCUBA 
diving,  1977,  A.  Deynzer  collection. 

Remarks:  The  small  size  of  the  present  species 
(figures  11,  12),  complemented  by  the  develop- 
ment of  elaborate  sculpture,  the  elongated  body, 
and  the  rich  coloring  serve  to  distinguish  this 
taxon  from  any  of  its  congeners. 

Favartia  dorothyae,  n.  sp. 

Figs.  3. 4. 15,16 

Description:  Shell  small  for  genus,  attaining  9 
mm  in  length,  broadly  fusiform;  spire  elevated 
but  small  in  proportion  to  body  whorl;  pro- 
toconch of  l'/2  whorls;  post-nuclear  whorls  6  in 
number;  suture  distinct.  Body  whorl  obese,  with 
a  small  ovate  aperture;  anal  sulcus  weakly- 
developed.  Lower  half  of  inner  lip  erect,  adherent 
above;  outer  lip  crenulated  and  sculptured  within 
by  7  long  lirae.  Anterior  end  of  columella  or- 
namented by  a  small  tooth.  Siphonal  canal  broad 
above,  tapering  and  distally  recurved;  siphonal 
fasciole  rostrate.  Body  whorl  with  5  major  cords 
and  with  one  major  cord  on  canal;  each  cord  sub- 
divided by  4  or  5  incised  lines.  Three  secondary 
cords  situated  above  the  major  cord  at  shoulder. 
A  secondary  cord  present  on  the  body  whorl 
below  the  second  and  third  cords.  A  major  cord 
appears  on  the  canal  with  secondary  cords  above 
and  below  it.  Additional  minor  spiral  cords  pre- 
sent on  the  body  as  well  as  over  the  shoulder. 
Five  varices  form  the  axial  sculpture.  Starting  at 


January  10. 1979 

Vol.  93(1) 

each  varical  margin,  the  cords  ascend  to  the 
strongly  developed  varix  where  they  terminate 
and  are  recurved  distally.  The  leading  side  of 
each  varix  bears  7  or  8  fimbriae  which  develop 
into  scaly  sculpture  over  the  whorls.  The  shell 
color  ranging  from  warm-white  to  carmine  with 
the  early  whorls  golden-hued;  characteristically 
with  the  cx)lumella,  the  dorsal  and  ventral  sides 
of  the  canal,  and  the  base  of  the  body  whorl  are 
all  strongly  colored  a  rosy  pink. 

Measurements:  Holotype  15.9  mm  in  length, 
width  9.6  mm;  smallest  paratype  (lacking  a 
mature  siphonal  canal)  13.7  mm  (AMNH  183822); 
largest  paratype,  16.2  mm  (SDMNH  no.  72624). 

Ti/pe  locality:  Off  Punta  Engano,  Mactan 
Island,  Philippines,  in  about  30  meters,  (obtained 
in  tangle  or  gill  nets),  1977,  ex  Dorothy  and 
Robert  Janowsky  collection. 

Material  examined:  Holotype  AMNH  183821 
(figures  3, 4),  and  three  paratypes  AMNH  183822, 1 
paratype  SDMNH  72624  (figures  15,  16,  AMNH 
183822a);  3  paratypes,  Janowsky  collection;  1 
paratype  Leo  Kempczenski  collection ;  all  from  the 
type  locality.  Three  specimens,  Panglao,  Bohol 
Island,  Philippines,  in  trap,  1977-1978,  A.  Deynzer 

Remarks:  This  species  (figures  3,  4,  15,  16)  with 
its  distinct  apertural  coloration  and  delicate 
frostlike  sculpture  may  be  easily  distinguished 
from  the  following  congeners:  F.  marjorae 
(Melvill  and  Standen,  1903),  to  which  it  bears 
some  resemblance,  by  comparison  with  a 
photograph  of  the  holotype  in  Radwin  and  D'At- 
tilio,  1976,  fig.  95,  p.  150.  F.  marjorae,  which  has 
a  less  swollen  body  and  a  higher  spire,  is  grey  in 
color  and  occurs  in  the  Persian  Gulf.  F.  balteata 
(Sowerby,  1841)  from  the  western  Pacific  has  a 
more  strongly  sculptured  shell,  with  well- 
developed  black  squarrose  varices,  and  has  a 
brown  shell  with  a  red  aperture.  F.  salmonea 
(Melvill  and  Standen,  1899)  has  a  comparatively 
higher  spire,  possesses  a  decided  gap  between  the 
body  cords  and  those  on  the  canal,  and  is  pale 
reddish  orange,  darkest  at  the  varices.  It  has  not 
been  reported  from  the  northern  area  of  the 
western  Pacific.  F  roaea  Habe,  1961,  (herein  il- 
lustrated, figures  5,  6),  from  southeastern  Japan, 
has  a  larger  (23  mm),  fleshy  orange  to  yellow  col- 

ored shell,  with  the  varical  areas  conspicuously 
more  rounded  (swollen),  and  the  surface  not 
noticeably  scabrous. 

Favartia  elatensis  n.  sp. 

Figs,  la  u 

Description:  Shell  small  for  genus,  attaining  8 
mm  in  length,  fusiform;  spire  high;  protoconch 
1'-:  rounded  whorls,  followed  by  5  post -nuclear 
whorls;  suture  distinct.  Aperture  ovate,  outer  lip 
strongly  undulate  reflecting  the  dorsal  sculpture; 
inner  lip  adherent;  anal  sulcus  broad  and  simple; 
canal  moderately  long,  narrowly  open,  tapering, 
weakly  recurved,  siphonal  fasciole  moderately 
developed.  Axial  sculpture  strong  with  growth 
lines  developing  into  widely  spaced  lamellae; 
vaulted  scales  formed  by  expansion  of  lamellae 
over  the  spiral  cords.  Six  varices  on  post-nuclear 
whorls  of  spire;  four  on  body  whorl.  Varices 
crossing  at  shoulder  diagonally  onto  contiguous 
whorl.  Spiral  sculpture  of  6  squarish  and  knobby 
cords  on  body  whorl,  with  one  cord,  on  the  canal; 
cords  grooved  spirally,  but  dividing  somewhat  ir- 
regularly into  unequal  widths,  to  form  unequal 
scaly  ornamentation.  Cords  at  the  varical 
margins  expanded  into  lobes;  final  varix  with  a 
recurved  margin.  Varical  areas  of  shoulder  ex- 
tending into  lobes  with  vaulted  edge  on  leading 
side.  Shell  color  uniformly  fleshy  white. 

Measurements:  Holotype  7.8  mm  in  length,  3.9 
mm  in  width;  largest  paratype,  7.9  mm  in  length 
(SDMNH  no.  63254a,  figures  14,  15);  smallest 
paratype  (immature)  4.2  mm  (HUJ  no.  10.202/8). 

Tt/])e  locality:  Elat,  Gulf  of  Elat,  Israel, 
29°32'-29°31'  N.,  36°58'-36°59'  E.,  in  190 
meters  from  grab  sample,  October  8,  1965. 

Material  examined:  Holotype  and  7  paratypes 
HUJ  10.202/8  fix)m  the  type  locality;  2  paratypes 
SDMNH  63254,  ex  HUJ  10.202/RS-18,  Elat,  Gulf  of 
Elat,  29°32'-29°31'  N.,  36°58'-36°59'  E.,  in  190 
meters;  1  paratype  AMNH  183823,  ex  HUJ 
10.204/1.  Elat,  Gulf  of  Elat.  29°31'-29°32'  N.. 
34°58'-36°59'  E.,  in  250  meters,  October  8,  1965;  8 
paratypes,  HUJ  10.203/9  Elat,  Gulf  of  Elat, 
29°3r-29°32'  N.,  ;34°58'-34°59'  E.,  in  80  meters. 

Remarks:  The  presence  of  squarely-formed 
spiral  cords  terminating  in  lobed  projections,  and 
the  relatively  small  size  of  the  shell  (figures  13, 

Vol.  93  (1) 

January  10. 1979 


14)  serve  to  distinguish  this  species  from  others 
in  the  genus.  This  species  is  presently  knowTi  only 
from  the  Gulf  of  Elat.  Although  Recent  Favartia 
are  not  recorded  in  the  Mediterranean,  some 
Indo-Pacific  species  with  shells  larger  than  that 
of  F.  elatensis  occur  intertidally  or  in  shallow 
depths  elsewhere  in  the  Red  Sea. 

Genus  Murexiella  Clench  and  Farfante,  1945 
Type    species:    Miirex   hidalgoi    Crosse.    1869.    by   original 

Murexiella  mactanensis  n.  sp. 

Figs.  7. 8 

Description:  Shell  medium-sized  for  genus,  at- 
taining 22  mm  in  length;  biconically  fusiform; 
spire  elevated,  with  5  convex  whorls;  protoconch 
dense  white  and  with  suture  impressed.  Aperture 
broadly  ovate;  peristome  erect,  more  weakly 
elevated  on  the  left  posterior  side;  margin  of 
outer  apertural  lip  wavy,  with  the  5  undulations 
reflecting  the  presence  of  the  external  cords;  anal 
sulcus  weak;  si  phonal  canal  moderately  long,  nar- 
rowly open;  tapering  tube-like  and  strongly 
recurved;  siphonal  fasciole  strong,  spaced  some 
distance  from  body  sculpture.  Axial  sculpture  of 
5  erect  varices  terminating  distally  as  open 
spines  of  moderate  height;  final  varix  set-back 
from  aperture,  bent  back  and  with  the  leading 
side  richly  scabrous;  scabrous  lamellae  on  leading 
side  of  all  varices  to  the  margin  of  each  varix:  in- 
tervarical  area  with  weaker  lamellae  or  with 
lamellae  developing  into  scales.  Spire  with  6 
varices,  the  varices  more  weakly  erect  crossing 
the  shoulder  diagonally  and  continuing  on  to  the 
varix  of  preceeding  whorl.  Body  whorl  with  5 
spiral  cords;  cords  nearly  erect  on  varices  and 
temiinate  as  upturned  spines.  Spines  at  shoulder 
longest;  the  first  two  paired,  followed  by  the  re- 
maining 3;  spines  open,  marginally  not  or- 
namented and  on  the  final  varix  broadest  distally 
with  the  edges  recurved  on  the  leading  side; 
spines  subdivided  lengthwise  by  incised  lines  into 
2  or  3  unequal  areas.  Minor  cords  situated  be- 
tween large  ones,  with  a  gap  between  the  last  cord 
on  the  body  and  the  spinal  cord  on  the  canal. 
Shoulders  ornamented,  notably  on  the  final  varix, 
with  a  short  lobe  having  3  or  4  pointed  spines. 

Shell  color:  on  the  holotype,  the  spire,  inter- 
varical  areas,  and  fasciole  flesh-pink,  darkest 
towards  the  apex;  varical  areas  white,  especially 
terminally:  aperture  white.  In  the  paratypes,  the 
amount  of  the  flesh-pink  coloration  varies  in  in- 
tensity and  location  on  the  shells. 

Memurements:  Holotype  21.7  mm  in  length, 
width  (including  spines)  14.3  mm;  smallest 
specimen  (4  post -nuclear  whorls;  Pisor  collection), 
length  12.9  mm. 

Type  locality:  Off  Punta  Engano,  Mactan 
Island,  Philippines,  in  about  30  meters  (obtained 
in  tangle  or  gill  nets),  1977,  ex  Dorothy  and 
Robert  Janowsky  collection. 

Material  examined:  Holotype  AMNH  no.  187186 
(figures  7,  8);  1  paratype  Panglao,  Bohol  Island, 
Philippines,  in  about  180  meters,  1977,  Albert 
Deynzer  collection;  1  paratype  SDMNH  7:3800  (ex 
Pi.sor  collection)  and  1  paratype  Don  Pisor  collec- 
tion, both  Bohol  Straits,  Philippines,  in  about  50 

Remarks:  The  present  species,  characterized  by 
having  the  5  varices  terminating  in  simple,  unor- 
namented  spines,  may  be  assigned  to  Murexiella 
(sensu  stricto),  based  on  the  typological  genus- 
group  concept  of  Murexiella  Clench  and  Pe'rez 
Farfante,  1945  (see  Radwin  and  D'Attilio,  1976,  p. 
155-161).  Several  western  Pacific  species  were 
assigned  by  Ponder  (1972)  to  Murexiella.  which 
he  regarded  as  a  subgenus  of  Favartia.  These 
other  taxa  differ  from  the  new  species  by  their 
closer  relationship  to  Favartia  (sensu  stricto). 
Comparison  can  be  made  with  the  Indo-Pacific 
species  F.  salmonea  (Melvill  and  Standen,  1899) 
and  F.  voor-unndei  Ponder,  1972,  in  which  the 
body  whorl  and  sculpture  are  somewhat  similar. 
They  lack,  however,  well -developed  spines  with 
connecting  webbing,  characters  that  serve  to 
distinguish  taxa  referable  to  Murexiella  (sensu 
strict(i)-  This  new  species,  together  with  the  one 
following,  brings  to  two  the  number  of  distinctive 
Murexiella  recognized  recently  in  the  central 

Murexiella  martini  Shikama,  1977 

Figs.  9, 10 

Supplemental  description:  A  slender  fusiform 
shell,  attaining  28  mm  in  height  (holotype);  spire 

8       THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 


FIG.  19.     Pteropurpura  benderskyi  n.  xp.,  radular  dentition 
(drawirigs  by  Anthony  D'Attilio);  greatly  enlarged. 

well -elevated,  with  a  protoconch  of  1"4  whorls, 
followed  by  6  post-nuclear  whorls;  body  whorl 
large,  strongly  spined  at  shoulder;  suture  im- 
pressed. Aperture  ovate,  peristome  entire  and 
strongly  elevated;  sulcus  shallow  and  broad; 
outer  lip  with  4  extended,  lobe-like  crenulations 
reflecting  the  dorsal  spiral  sculpture.  Siphonal 
canal  narrowly  open,  broad  above,  strongly 
recurved,  tapering  axially  and  tube-like  distally, 
with  fasciole  formed  by  terminations  of  the  two 
previous  canals.  Body  whorl  with  3  spinose 
varices;  varical  margins  thick,  erect  and  continu- 
ing nearly  midway  to  the  intervarical  area;  basal 
varix  crossing  the  shoulder  diagonally  and  ex- 
tending to  the  previous  whorl.  Four  strong  spiral 
cords,  one  at  shoulder  separated  by  a  gap  from 
the  group  of  3  below;  cords  terminating  in  long 
moderately  open  spines  at  the  varices;  spine  at 
the  shoulder  longest,  those  below  about  '  2  as 
long;  cords  subdivided  by  3  to  .5  incised  lines. 
Spines  connected  by  a  flangelike  web  ornamented 
with  a  scabi-ous  lamellate  surface  on  the  leading 
side;  varical  webbing  with  one  .small,  medial  cord 
and  with  a  weakly  defined  cord  on  either  side  of 
the  central  cord.  Scaly  lamellae  on  entire  surface 
of  the  shell,  exclusive  of  the  canal,  and  with 
prominent  lamellar  development  on  the  raised 
cords  and  .spines.  Shell  pale-brown  ochre,  lighter 
dorsally  on  the  cords  and  spines,  darker  brown 
on  the  open  inner  surface  of  the  cords  and  on  the 
varical  margins;  aperture  and  peristome  translu- 

cent whitish.  Color  somewhat  variable  among  the 
10  specimens  examined. 

Measurements:  Largest  specimen  examined 
26.6  mm  in  length,  width  (excluding  spines)  9.5 
mm;  smallest  specimen  (lacking  mature  siphonal 
canal)  18  mm  in  length,  width  (e.xcluding  spines) 
7.6  mm,  Ribbey  collection. 

Type  locality:  Off  C€bu  Island,  Philippines. 

Type  depository:  Personal  collection  of  Dr. 
Tokio  Shikama,  Yokohama,  Japan. 

Material  examined:  Figured  specimen  SDMNH 
no.  72627  (figures  9,  10)  and  1  other  specimen, 
Bohol  Island,  Philippines,  I.^o  Kempczenski  col- 
lection; 3  specimens  from  off  Punta  Engano,  Mac- 
tan  Island,  Philippines  Islands,  Janowsky  collec- 
tion; 1  specimen,  Mactan  Channel,  Philippines,  in 
tangle-trawl,  Bibbey  collection;  1  specimen 
AMNH  no.  183818,  from  Samar  Island,  Philip- 
pines, ex  Bibbey  collection;  2  specimens,  Panglao, 
Bf)hol  Island,  Philippines,  in  trap,  1977-1978, 
Deynzer  collection. 

Remarks:  This  distinctive  western  Pacific 
species  (Shikama,  1977,  p.  1,5.  pi.  2,  figs.  10a,  10b) 
is  characterized  by  the  relatively  small  size  of  the 
body  whorl,  the  slightly  extended  spire,  the 
lengthy  spines,  and  prominent  webbing  (figures  9, 
10).  It  was  compared  by  Shikama  (1977.  p.  15)  to 
several  unrelated  long-spined  species:  Chicoreus 
damicornis  (Hedley,  1903),  C.  ojcicomis  (Lamarck, 
1822),  and  Murex  lonyiconiiii  Dunker,  1864. 

Genus  Siphonocheluii  Jousseame,  1880 
Type  species:   Tijphix  areiiatiix  [sic]  Hinds.  1844   (  =  7*.  ar- 
cuatiis  Hinds,  1843),  by  original  designation. 

Siphonochelus  radwini  n.  sp. 

Figs.  20, -jl 

Description:  Shell  small  for  genus,  attaining  5 
mm  (holotype  immature,  lacking  perhaps  one 
body  whorl),  fusifomi;  spire  acute,  of  !'<  bulbous 
nuclear  whorls,  followed  by  3  weakly  angulate 
ix)stnuclear  whorls;  suture  impressed.  Body  whorl 
lai'ge.  fusoid;  aperture  small,  ovate  with  an  entire 
and  erect  peristome.  Anal  sulcus  apparently  lack- 
ing, but  with  a  moderately  long  anal  tube,  arising 
at  the  rounded,  poorly  defined  margin  of  shoulder 


January  10, 1979 



FIGS.  20  and  21,  Siphonochelas  radwini  n.  sp..  Iwluttjpe. 
NMNH  323198  (drmdngs  by  Anthony  D'Attilio);  greatly 
enlarged  (mt II ml. tize  =  5.0  mm.  In  length). 

in    each    varical    interspace,    and    more    closely 
placed  to  the  earlier  of  the  two  varices.  Proximal 
portion  of  each  tube  on  the  body  swollen  and  ax- 
ially  depressed  on  the  left  side  below  the  shoulder 
margin.  A  minor  swelling  produced  on  the  lead- 
ing side  of  each  tube,  terminating  as  a  fold  at  the 
margin  of  the  shoulder.  Distal  portion  of  tubes 
generally  short,  slanted,  and  irregular  in  cross- 
section.   Last  tube  largest,  weakly  bent  to  the 
right,  and  the  only  one  remaining  open.  Body 
whorl  with  4  varices:  each  varical  margin  with  a 
slight  axial  thickening  corresponding  to  a  former 
outer  apertural  lip.  With  increasing  whorl  size, 
position  of  each  tube  slightly  ahead  (in  the  direc- 
tion of  growth)  of  the  corresponding  tube  on  the 
preceeding  whorl.  Siphonal  canal  broad,  moder- 
ately short,  tapering,  closed,  bent  to  the  right  and 
dorsally  recurved.  Shell  dull-white;  aperture 
polished  white. 

Mea.'^urements:  Holotype  (figure  20,  21),  length 
5.0  mm,  width  2.5  mm. 

Tijpe  locoUty:  Off  Cabo  Catoche,  Yucatan,  Mex- 
ico, dredged  in  46  meters,  USBF  Sta.  2361. 
Material  studied:  Holotype  NMNH  323198. 
Remarh:  We  have  followed  the  genus-group 
concept  of  Radwin  and  D'Attilio  (1976,  pp.  198- 
200)    in    assigning   this   new   species   to   Sipho- 
nochdm.  the  first  record  of  a  living  represen- 
tative of  this  genus  from  the  New  World.  Addi- 
tional   living    species    of   Siphnnochelus    are 
recorded    by    these    authors    from    the    western 
Pacific  and  from  off  the  Cape  of  Good  Hope.  It 
should  be  noted,  however,  that  Radwin  and  D'At- 
tilio (1976)  rejected  the  previous  assignment  by 
several  authors  of  western   Atlantic  species  to 
Siphonnchehis  (e.g.:  Keen,  1944;  Gertman,  1969; 
and  Bayer,  1971):  see  also  Penna-Neme  and  Leme 
(1978)    for   their   use   of  Siphoriochelus   for   an 
eastern  American  species. 

Although  this  taxon  is  based  on  a  unique,  ap- 
parently immature  specimen,  its  distinctive 
morphology,  together  with  its  occurrence  in  the 
Western  Hemisphere,  has  led  us  to  describe  it. 


Bayer.  F.  M.  1971.  Biological  results  of  the  Univereity  of 
Miami  Deep-Sea  Expedition  79.  New  and  unusual  moUusks 
collected  by  R/V  -John  Elliot  Pilhbury  and  RA^  Gerda  in 
the  tropical  western  Atlantic.  Bnll.  Mar.  Sri.  21(l):lll-236. 
72  figs. 

10      THE  NAUTILUS 

January  10. 1979 

Vol.  93(1) 

Bivona-Beraardi.  A.  IKfi.  Caratteri  di  alcune  specie  de  con- 

chiglie, estratti  come  sopra.  F^fem  Sci.  Lett.  Sicitia  1 16-24. 
Blainville,   H.  M.  D.  de.   1829.  Fauna  franpise  ou  histoire 

naturelle,    gene'rale,    et    particuliere    des    animaux    qui 

retrouve  en  France.  Moilusques.  Levraux,  Paris  1-320.  pis. 

Clench,  W.  .J.,  and  1.  Pe'rez  Farfante.  1945.  The  genus  Murex 

in  the  western  .■Mlantic.MH.s-oHiVi  1(17):1-,t6,  pis.  1-28. 
Crosse.  H.  1869.  Diagnosis  moiiuscorum  novorum.  Jmtrn.  de 

Coiichyl.  n-.-m-iW. 
De.shayes.  G.  P.  18.39.  Nouvelles  especes  de  moilusques.  prove- 

nant  des  c3tes  de  la  Californie,  du  Mexique.  du  Kamt- 

schatka    et    de    la    Nouvelle    Zelande.    d&rites    par    M. 

Deshayes.  Rev.  Zool.  Soc.  Qmerierenne.  2:.356-61. 
Dunker.    W.    1864.    Fiinf   neue    Mollusken.    Malak.    Bliitt. 

Gertman.  R.  1969.  Cenozoic  Tj'phinae  (Mollusca:  Gastropoda) 

of  the  western   Atlantic   region.   Txlaiie  Stud.  Ceol.   and 

Meant.  7(4):  14.3-191,  pis.  1-8. 
Habe.  T.  1961.  Caloured  illmtratians  of  the  shelh  < if -Japan 

[vol.  2].  Hoikusha,  Osaka.  183  p..  66  pis. 
Habe.  T..  and  S.  Kosuge.   1971.  Pacific  Shell  News.  Tokyo. 

Japan.  (3):7.  (Published on  October  30, 1971). 
Hedley.  C.  190.3.  Scientific  results  of  the  trawling  expedition 

of  H.  M.  C.  S.  Thetis  off  the  coast  of  New  South  Wales  in 

Feb.    and    Mar.,     1898,    pt.    6.    Mem.    Australian    Mus. 

4(l):.326-402,  pis.  36-38.  figs.  61-1 13. 
Hinds,  R.  B.  1843.  On  new  species  of  shells  collected  by  Sir 

Edward  Belcher.  C.  B.  Proc.  Zool  Soc.  London,  for  1843. 

11: 17-19  (July.  1843). 
1844.   The  zoology  of  the  voyage  of  H.  M.  S. 

Sidphur.  London.  Mollusca,  pt.  1, 1-^4,  pis.  1-7  (July,  1844). 
Jousseaimie,  F.  1880.  Division  methodique  de  la  famille  des 

Purpurides.  Le  Naturaliste,42:.3a5-336. 
Keen,  A.  M.  1944.  Catalogue  and  revision  of  the  gastropod 

subfamily  Typhinae.  Jour.  Pcdeont.  18(l):.50-72. 20  figs. 

I^niarck.  J.  B.  P.  A.  1822.  Hittoire  naturelle  des  animaux 

.sfiH.s  veiiebrex.  Paris.  7,  232  pp. 
Melvill.  J.  C.  and  R.  Standen.  1899.  Report  on  the  marine 

Mollusca  obtained  during  the  first  expedition  of  Prof.  A.  C. 

Haddon  to  the  Torres  Straits  in  1888-1889.  Jour.  Linn.  Soc. 

London.  27:1.50-206.  pis.  1, 2. 
190.3.  Descriptions  of  68  new  Gastropoda  from  the 

Persian  Gulf.  Gulf  of  Oman  and  N.  .Arabian  Sea  dredged  by 

Mr.  F.  W.  Townsend  of  the  Indo-European  Telegraph  Svc. 

1901-190,3. .4«n.A/as.A'a/.  Hist.  12:289-.324.  pis. 20-23. 
Monterosato,  T.  A.  di.  1890.  Conchiglie  della  profundita  del 

mare  di  Palermo.  A^a<.  Sicil.  9:140, 1.51, 157-66, 181-91. 
Penna-Neme,  L.,  and  J.  L.  Moreira  Leme.  1978.  Novas  especies 

e    novas   ooorrencias   de   gastropodos   marinhos   na   costa 

Brsisileira.  Pap.  Avidsos  Zool,  SSb  Paulo  31(18):283-297,  33 

Ponder,  W.  F.  1972,  Notes  on  some  Australian  genera  and 

species   of  the    family    Muricidae    (Neogastropoda).   Jour. 

Malac.  Soc.  Austral.  2(3):215-248. 
Radwin.  G,  E..  and  A.  D'Attilio.  1976.  Murex  Shells  of  the 

World,   an    illastrated  guide   to  the   Muricidae.   Stanford 

Univ.  Press.  284  p..  32  pis..  198  text  figs. 
Shikama.    T.    1977.    Descriptions    of   new    and    noteworthy 

Giistropoda  from  western  Pacific  and  Indian  Oceans.  Set. 

Reixiiis,  Yokohoma  Natl.  Univ..  sect.  2.  Biol,  and  Geol.  Sci., 

no.  24:9-23.  pis.  1-5. 2  figs. 
Sowerby,  G.  B.  II.  1834.  The  conchological  illustrations,  Murex. 

London,  pis.  .58-67. 

1841.  Ibid.,  pis.  187-189,  and  catalogue,  p.  1-9 

Yokes,  Emily  H.   1975.  Cenozoic  Muricidae  of  the  western 

Atlantic  r^ion.  Pt.  6,  Aspella  and  Dermomurex.   Tiilane 

Stud.  Geol  and  Paleont.  11(3):  121-162,  pis.  1-7. 
Wanner.  J.  and  E.  Hahn.  193.5  Miocane  Mollusken  aus  der 

Liindschafe  Rembang  (Java).  Zeitsch.  Deutsch.  Geol  Gesell. 

Berlin  87(4):222-273,  pis.  17-21. 


William  K.  Emerson 


William  E.  Old.  Jr. 

Department  of  Invertebrates 

American  Museum  of  Natural  History 

New  York.  N.  Y.  UX)24 


Scaphella  contoyensis,  a  new  species  from  the  Yucatan  Channel,  Mexico,  is 
desciibed  and  compared  urith  related  volutid  species  of  the  New  World  subfamily 

During  the  past  decade,  several  examples  of  a 
large,  thin-shelled  volute  have  been  obtained  by 
shrimpers  in  depths  ranging  from  about  70  to  180 

meters  in  the  Yucatan  Channel,  mostly  in  the 
vicinity  of  Contoy  Light,  off  Cabo  Catoche, 
Yucatan,  Mexico.  These  specimens  are  somewhat 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      11 

reminiscent  of  Australian  species  of  Ericusa  and 
Cymhiolista  in  size  and  coloration,  but  they  lack 
the  spinose  ornamentation  that  characterizes  the 
latter  Indo-Pacific  forms. 

Specimens  of  the  new  species  were  generously 
donated  to  us  by  Donna  and  Riley  Black  and 
Elsie  Malone  of  Ft.  Myers,  Florida,  and  Dr. 
William  J.  Clench  of  Dorchester,  Massachusetts. 
Gene  Everson  of  Ft.  Lauderdale,  Florida,  kindly 
lent  a  specimen  from  his  collection  and  donated 
the  soft  parts.  These  specimens  fonu  the  basis  for 
the  present  report.  Additional  specimens,  all 
taken  by  dredging  in  the  Yucatan  Channel,  are 
preserved  in  the  following  private  collections: 
Christine  S.  Goddard  of  Ft.  Myers  Beach,  Florida, 
1  specimen,  in  46  meters,  March  1968.  Barbara 
and  Thomas  McGinn  of  Cutoff,  Louisiana,  8 
specimens  (2  of  which  are  now  in  the  collection  of 
the  American  Museum  of  Natural  History),  in 
132  to  183  meters,  February  1970,  (1  specimen), 
March,  1972  (6  specimens),  1975  (1  specimen); 
Elsie  Malone  of  Ft.  Myers,  Florida,  1  specimen  in 
90  meters,  ex  Carmel  and  Wassy  Frank  collection; 
Carmel  and  Wassy  Frank,  Ft.  Myers,  Florida,  2 
specimens  (teste  Elsie  Malone);  and  Ernie 
Ryckman,  of  Key  West,  Florida,  1  specimen.  We 
are  grateful  to  these  collectors  for  providing  data 
and  photographs  of  their  specimens. 

Drs.  Frederick  M.  Bayer  and  Joseph  Rosewater 
of  the  National  Museum  of  Natural  History  also 
contributed  data,  and  the  latter  lent  us  the 
holot>T3ic  specimen  of  Scaphella  evelina  Bayer. 
Our  colleague,  G.  Robert  Adlington,  photographed 
the  specimens  illustrated  in  this  paper. 


Bayer  (1971,  pp.  200-221)  succintly  reviewed  the 
pertinent  literature  pertaining  to  the  classifica- 
tion of  the  western  Atlantic  species  of  Volutidae 
[q.v.,  Clench,  1946,  1953;  Clench  and  Turner,  1964, 
1970;  Olsson,  1965;  Pilsbry  and  Olsson,  1953,  1954, 
and  Weaver  and  duPont,  1970).  We  concur  with 
Bayer's  conclusion  that  the  classification  of  the 
family  is  ".  .  .  still  a  difficult  matter,"  as  the 
genus-group  assignment  of  the  Scaphella 
described  herein  proved  to  be  perplexing  because 
of  conflicting  data.  We  must,  however,  comment 
on  Bayer's  (1971,  p.  195)  placement  of  the  genus 

Teramarhia  Kuroda,  1931,  in  the  family  Tur- 
binellidae,  based  largely  on  shell  characters  in 
the  absence  to  him  of  information  on  the  radula. 
Anthony  D'Attilio  (in  litt.)  has  pointed  out  to  us 
that  the  radular  characters  of  T.  tlbiaefonnis 
Kuroda,  1931,  the  type  species  of  Teramachia,  as 
illustrated  by  Habe  (1952,  p.  132,  fig.  12),  are 
typically  volutid.  This  genus  is,  therefore, 
referable  to  the  subfamily  Calliotectinae  Pilsbry 
and  Olsson,  1954,  on  the  basis  of  radular  and 
opercular  morphology  (v.  et..  Weaver  and  duPont; 
1970,  p.  177,  fig.  41b,  for  an  illustration  of  the 

In  the  most  recent  reviews  of  the  subfamily 
Scaphellinae,  Bayer  (1971,  pp.  209-216)  and 
Weaver  and  duPont  (1970,  pp.  140-145)  recog- 
nized the  genus  Scaphella  as  a  polytypic  taxon  to 
include,  in  addition  to  the  nominate  subgenus, 
the  subgenera:  Qenchina.  Pilsbry  and  Olsson, 
1953  (type  species  by  original  designation:  Voliita 
dohrni  Sowerby,  1903,  =  S.  govMiana  (Dall, 
1887),  fide  Abbott,  1974,  p.  244)  and  Aurinia  H. 
and  A.  Adams,  1853  (type  species  by  original 
designation:  Volutia  dubia  Broderip,  1827).  The 
subgeneric  units  were  separated  by  these  authors 
largely  on  the  basis  of  minor  differences  in  the 
radular  morphology,  as  defined  by  Pilsbry  and 
Olsson  (1954)  in  their  "Systems  of  the  Volutidae". 
According  to  Bayer  (1971,  p.  209,  and  fig.  63),  the 
t.vpe  species  of  Scaphella  (sensu  strkto),  Voluta 
junonia  Lamarck,  1804,  has  ".  .  .a  single  long, 
concave  cusp  and  no  small  basal  denticles.";  S. 
(Clenchina)  dohrni  has  "...  a  shorter,  more 
pointed,  concave  cusp  flanked  by  minute  acces- 
sory cusps.";  and  S  (Aurinia)  dubia,  together 
with  the  genus  Volutifusus  Conrad,  1863,  has 
".  .  .a  well -developed  lateral  cusp  on  each  side  of 
the  main,  central  cusp."  Bayer  concluded  that  the 
simple  Y-shaped  teeth  of  S.  junonia  had  resulted 
from  progressive  reduction  of  the  side-denticles 
from  the  well-developed  tricuspid  teeth  of  Au- 
rinia and  he  suggested  that  these  distinctions 
would  be  found  to  be  of  minor  taxonomic  sig- 
nificance, when  more  radular  data  became 
known.  The  radular  morphology  of  the  new  spe- 
cies of  Scaphella  described  herein  serves  to  sup- 
port Bayer's  thesis,  because  the  teeth  lack  basal 
denticles  (fig.  7),  in  contrast  to  the  denticled 
teeth  of  S.  evelina  Bayer  (1971,  fig.  63),  which  we 

12      THE  NAUTILUS 

January  10, 1979 

Vol.93  (1) 

believe  tx)  be  the  closest   known   relative  of  S! 
nint(iye))!iis,  n.  sp.  (see  remarks  below). 

In  addition  to  the  supposed  radular  differences, 
Scaphella  (sensu  stricto)  and  Scaphella  (Clen- 
china)  have  been  distinpuished  by  trivial  con- 
cholopical  characters,  including  the  possession  by 
the  latter  of  less-solid  shells  than  those  of  S. 
junonki  (Weaver  and  duPont,  1970,  p.  140).  The 
basic  similarity  of  the  shell  morphology,  together 
with  the  minor  differences  of  the  radular 
characters,  however,  suggests  to  us  that  the 
genus-group  taxon  Genchim  is  of  questionable 
taxonomic  value  and  our  new  species,  together 
with  S.  eveiina,  should  be  assigned  to  Scaphella 
(sensu  stncto). 

Family  Volutidae 

Subfamily  Scaphellinae 

Genus  Scaphella  Swainson,  1832 

Type  species:  Valuta  jmumia  Lamarck.  1804,  by  subseciuent 
designation.  Herrmannsen.  1848,  p.  423. 

Scaphella  contoyensis,  n.  sp. 

Figures  1  -7 

Description:  Shell  fusiform,  large  (attaining 
170+  mm  in  length),  with  6  whorls.  Protoconch 
large  and  .smooth,  consisting  of  about  2  whorls. 
The  first  three  post-nuclear  whorls  are  thicker 
and  more  solid  than  the  fragile  body  whorl, 
which  is  thin  and  inflated  in  mature  individuals. 
The  first  2  post-nuclear  whorls  sculptured  with 
fine  intersecting  spiral  and  axial  cords  that  give 
a  weakly  cancellate  appearance  to  the  surface 
(figure  5).  Surface  sculpture  of  the  third  post- 
nuclear  whorl,  especially  posteriorly  near  the 
suture,  is  microscopically  cancellate,  but  the 
sculpture  is  scarcely  perceptible  and  the  surface 
becomes  macroscopically  smooth  on  the  body 
whorl.  Spire  short,  not  acutely  angled;  .suture 
well-defined,  moderately  impressed.  Aperture 
elongate-elliptical;  outer  lip  thin  and  the  parietal 
wall  thinly  glazed.  Anal  sulcus  narrow  and  con- 
stricted [wsteriorly;  .si phonal  canal  broadly  ex- 
tended. Columella  slightly  arched,  with  two  plica- 
tions extending  within  the  aperture.  Periostra- 
cum  tannish  yellow  and  exceedingly  thin. 

Color  of  nuclear  whorls  is  uniformly 
brown;  ground  color  of  second  and  third 
nuclear   whorls   buff,   overlaid    with   two   spiral 

rows  of  irregular,  elongated,  chestnut-brown 
spots;  ground  color  of  third  post-nuclear  whorl 
and  body  whorl  is  a  darker  buff,  with  in- 
terspersed spiral  bands  of  chestnut-browTi  streaks, 
which  are  lighter  than  the  earlier  chestnut-brown 
spots.  In  mature  specimens,  the  interior  edge  of 
the  outer  lip  (figure  3)  has  a  c-ontinuous  band  of 
dark  brown  and  the  aperture  is  glossy,  tannish- 
yellow  to  apricot. 

Softpaiis:  Length  of  foot,  after  preservation  in 
alcohol,  78  mm;  color-base  whitish,  with  irregular 
dark  markings  that  are  preserved  as  black 
blotches  (figure  6).  Radula:  Reduced  to  simple  Y- 
shaped  rachidian  teeth  lacking  basal  denticles 
(figure  7).  An  operculum  is  lacking. 

Measurements:  Holotype  173  mm  in  length, 
67.3  mm  in  width;  figured  male  paratype,  length, 
70  mm  in  width  (Everson  collection);  smallest 
specimen,  immature,  with  three  post-nuclear 
whorls,  56.5  mm  in  length  (McGinn  collection). 
Slender  female  specimen,  166  mm  in  length,  58.5 
mm  in  width  (AMNH  collection,  ex  McGinn  and 

Tiipr  liKvlity:  of  Contoy  Light, 
Yucatan  Channel,  Mexico,  dredged  in  159  meters, 
September  1973,  by  Donna  and  Riley  Black. 

Ti/pe  specimens:  Holotype,  AMNH  187180 
(figures  1,  2,  5);  paratype  (figures  3,  4),  north- 
west of  Contoy  Light,  off  Yucatan,  Mexico, 
dredged  in  73  meters,  March  1978,  Gene  Everson 
collection.  Paratype  AMNH  182250,  trawled  off 
Punta  Francisca,  Yucatan,  Mexico,  in  183  meters, 
March  1972,  ex  McGinn  collection. 

Kmnrn  range:  Yucatan  Channel,  off  Cabo 
Catoche,  in  73  to  160  meters,  and  off  Punta  Fran- 
cisca, in  183  meters,  Yucatan,  Mexico. 

Remarks:  Scaphella  contoyensis  n.  sp.  appears 
to  be  most  closely  related  to  Scaphella  rrrlina 
Bayer  (1971,  p.  213-216,  figs.  63c,  64),  a  species 
described  from  off  eastern  Panama  and  Colombia, 
in  depths  of  137  to  641  meters.  Bayer's  taxon 
diffei's  from  the  present  species  by  the  i>).s.session 
of  an  acute  spire,  in  the  development  of  much 
stronger  cancellate  .sculpture  and  a  less  fiaring 
outer  lip,  and  by  the  pre.sence  of  a  less  distinctive 
and  apparently  inconsistent  color  pattern,  as  well 
as  by  the  radular  characters  discussed  abive. 

Vol.  93(1) 

January  10. 1979 

THE  NAUTILUS      13 

FIGS.  1-6  Scaphella  rontoyensis  n.  sp.  1,  2  hjUdtnu.  AMXH  lH7im.  X'A:  1,  Apetliiral  vieu;  note  immature  outer  lip:  2,  Dfrrsal 
i'iev.  3,  4,  Paratifpe.  Erersim  collection.  .Y'  ?;  3,  Apetiural  i-ieic.  note  mature  outer  lip  uith  dark  colored  hand  on  interim-  edge  of 
the  outer  lip:  4,  Dorsal  vieu:  5,  Enlargement  of  the  apical  region  if  the  holotijpe.  showing  weak  cancellate  sculpture.  X2.  6,  Body 
oftheparatype  specimen  illustrated  in  figs.  2, 3,  X'l:  soft  parts  contracted  hijpre.'^erration  in  alcohol  and  sans  the  liver 

The  development  of  cancellate  sculpture  in  this 
subfamily  varies  considerably  among  the  species- 
group  taxa  and  within  some  populations  of  these 
taxa.  Of  the  extinct  species  that  are  most  closely 
related  to  S  junonia.  the  early  post-nuclear 
whorls  are  weakly  to  moderately  cancellate  in  S 
trenholmu  (Tuomey  and  Holmes,  1856)  from  the 
Miocene  and  S.  floridana  (Heilprin,  1887)  from 
the  Pliocene.  In  the  Miocene  species,  S.  precursor- 
Gar  Aner.  1948.  however,  post -nuclear  whorls  are 
strongly  sculptured  and  a  spiral  row  of  regularly 

spaced  nodules  are  found  immediately  below  the 
sutures  on  the  earlier  whorls  and  the  body 
whorl;  the  postsutural  nodules  become  obsolete 
and  replaced  by  wavy  spiral  cords  and  prominent 
axial  ribs  on  the  remainder  of  the  body  whorl  in 
mature  specimens.  In  the  living  species,  weak  to 
moderate  cancellate  sculpture  occurs  on  the  sec- 
ond and  third  pt«t-nuclear  whorls  of  some  in- 
dividuals of  S  junonia  and  S.  gouldiana  (especial- 
ly in  the  fornis  named,  S.  robusta  (Dall,  1889)  and 
S  mationae  (Pilsbry  and  Olsson,  1953),  some  ex- 

11      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

FIG.  7.  The  outline  of  a  rachidian  tooth  o/ Scaphella  con- 
toyensis  n,  sp.;  greatly  enlarged. 

amples  of  which  possess  nodular  spiral  bands  on 
the  earlier  whorls.).  All  of  the  specimens  of  5. 
contoyensis  n.  sp.  and  S.  evelina  that  we  have  ex- 
amined have  cancellate  sculpture  on  the  early 
whorls  and  near  the  suture  on  the  body  whorl.  In 
the  case  of  the  former  species,  this  sculpture  is 
essentially  microscopic,  whereas  in  the  latter 
species  it  is  easily  seen  by  the  naked  eye. 


Abbott.  R.  T.  1974.  Amerimn  Seashetls.  New  York,  663  pp.,  24 

Adams,  H.  and  A.  Adam.s.  18.5.3  [-1&58].  ne  Genera  of  Recent 

Motlusca.  3  vols..  London. 
Bayer,  F.   M.   1971.   Biological   results  of  the  University  of 

Miami     Deep-Sea     Expeditions.    79.     New    and    unusual 

mollusks  collected  by  R/V  John  Elliott  Pilhbtiry  and  RA' 

Ge)-(l(t   in   the  tropical  western   Atlantic.   Bull.   Mar.  5>ci.. 

21(l):lll-236,  72  figs.  ("March  i.ssue".  published  on  .June  16, 

1971;  reprinted,  in  Studies  in  Tropical  American  Mollusks. 

pp.  111-236.  Univ.  Miami  November  1. 1971). 
Broderip.  VV.  .J.  1827.  Description  of  some  new  and  rare  shells. 

Zool.  Journal.  3(9):81-85,  pis.  3-4. 
Clench,  W.  ,1.  1946.  The  genera  Bathyaurinia.  Rehderia  and 

Scaphelhi  in  the  western  Atlantic.  .Jnhn.iinmi.  2(22):41-6(), 

pis.  24-31. 
1953.  The  genera  Scaphetta  and  Aunniopsis  in 

the  western  Atlantic.  Ibid..  2(.32):.376-380.  pis.  186-187. 
Clench,    W.    ,1.   and    R.    D.    Turner.    19frl.    The    subfamilies 

Volutinae,  Zidoninae.  Odontocymbiolinae.  and  Calliotectinae 

in    the    western    Atlantic.    Jnhnsonia,    4(43):  129-180,    pis. 


.  1970.  The  family  Volutidae  in  the  western  Atlan- 
tic. Ibid.,  4(48)::«9-.372.  pis.  172-174. 
Conrad,  T.  A.  1863.  Catalogue  of  the  Miocene  shells  of  the 

Atlantic  Slope.  Pmc.  Amd.  Nat.  Sci.  Philadelphia,  for  1862, 

Dall,  W.  H.  1887.  [Correspondence],  Conchologists'  Exchange 

[The  Nautilus],  2(1):  9- 10. 
.  1889  Report  of  the  Mollusca.  Part  II.  Gastropoda 

and  Scaphopoda.  Reports  on  the  results  of  dredging  ...  in 

the  Gulf  of  Mexico  (1877-78)  and   in   the  Caribbean   Sea 

(1879-80).  by  the  U.  S.  Coast  Survey  steamer  "Blake"  .  .  . 

Bull.  Miut.  Comp.  Zool..  Harvard  Univ..  18:1-492.  pis.  10-40. 
Gardner.  .J.  1948.  Mollusca  from  the  Miocene  of  Virginia  and 

North  Carolina,  Pt.  2.  Scaphopoda  and  Gastropoda.  U.  & 

Geol.  Sun:  Prof  Paper  199-B,  179-310. 24-.38. 
Habe,   T.    19.52.  Pholadomyidae,   Clavagellidae.    Pandoridae, 

■luliidae  .  .  .  Rlmtrated  Catalogue  of  Japanese  Shells.  No. 

18.PP.  121 -132,  pi.  18, 28  figs. 
Heilprin,  A.  1887.  Explorations  on  the  west  coast  of  Florida 

and  in  the  Okeechobee  wilderness.  TVan.s.  Wagner  Free  /«.</. 

&•(■..  I:l-i:i4, 19  pis. 

Herrmannsen,  A.  N.  1848  [1846-18.52].  Indicis  Generum 
Malacozoiman  Primordia.  Cassel,  2  vols,  and  supplement. 

Kuroda,    T.    1931.    Two    new    species   of   Volutacea.    Ventts 

Lamarck,  J.  B.  P.  A.  1804.  Memoire  sur  deux  especes  nouvelles 

de  volutes  des  Mers  de  la  Nouvelle-Holland.  Am.  Mus.  Nat. 

dWM.  Nat.  Paris, 5:154-160,  pi.  12. 

Olsson,  A.  A.  1965.  A  review  of  the  genus  Voluta  and  the 
description  of  a  new  species.  Bidl.  Amer.  Paleont., 
49(224):6.53-672,  pis.  80-83. 

Pilsbry.  H.  A.,  and  A.  A.  Olsson.  19.5.3.  Materials  for  a  revision 
of  east  coast  and  Floridian  volutes.  The  Nautilus  67(1):1-13, 
pis.  1-3. 

1954.   Systems  of  the    Volutidae.   Bull.  Amer. 

Paleont..  35(152):271-306,  pis.  25-28. 

Sowerby,  G.  B.,  III.  1903.  Descriptions  of  new  species  of  Nassa, 
Purpura,  Latirus,  Voluta,  Conns,  Stomatella.  and  Spon- 
dylus.  Jour.  Malacology  10(3):73-77,  pi.  5. 

Swainson.  W.   [1831-]   1832.  Zoological  Rlustrations.  Ijondon. 

ser.2. 2(11-20).  pis.  46-9L 
Tuomey.  M.  and  F.  S.  Holmes.  18.56.  Pleiocene  [sic]  fossils  of 

South  Carolina,  containing  descriptions  and  figures  of  the 

Polyporia,  Echinodermata,  and  Mollusca.  Charleston,  South 

Carolina.  1.52  pp..  30  pis. 

Weaver.  C.  S..  and  .1.  E.  duPont.  1970.  Living  Volutes,  a 
monograph  of  the  Recent  Volutidae  of  the  world.  Mong.  Ser. 
no.  1,  Delaware  Mus.  Nat.  Hist.,  xv  -I-  375  pp.,  79  pis.,  43 
figs.,  13  maps. 

Vol.  93(1)  January  10, 1979  THE  NAUTILUS      15 


W.  Stephen  Thomas 

Director  -  Emeintus 

Rochester  Museum  and  Science  Center 

Rochester,  New  Yorl<  14610 

Andrew  Garrett  was  an  American  explorer, 
naturalist  and  artist  who  specialized  in 
malacology  and  ichthyology.  He  gathered  and 
studied  forms  of  many  other  invertebrates,  such 
as  corals  and  echinodenns,  and  made  careful 
drawings  of  them.  He  also  collected  specimens  of 
insects,  birds,  plants,  and  a  few  anthropological 
artifacts,  some  of  which  are  doubtlessly  resting 
anonymously  in  museums  or  private  collections. 
He  also  described  and  drew  watercolors  of  several 
dozen  species  of  shells  and  several  hundred  fish, 
many  of  which  are  as  yet  unpublished. 

Garrett  lived  and  worked  in  various  areas  of 
the  Pacific  Ocean  from  the  Hawaiian  Islands  to 
Fiji,  the  Marshall  Islands,  the  Gilberts,  Samoa, 
Tonga,  the  Cook  Islands  and  the  Society  group. 
From  1856  to  the  early  1870's,  his  most  produc- 
tive years,  he  spent  much  of  his  time  as  a  collec- 
tor for  Professor  Louis  Agassiz  of  Hai-vard  Col- 
lege and  in  the  latter  part  of  this  period,  from 
1873-5,   served    in    the    same   capacity    for   the 
zoological  and  anthropological  museum  of  the  J. 
C.    Godeffroy    trading    firm    of   Hamburg,   Ger- 
many. In  the  last  fifteen  years  of  his  life,  while 
located  permanently  in  French  Polynesia,  he  ad- 
ded to  his  own  vast  collection  of  shells,  part  of 
which  he  occasionally   sold  and   exchanged.   He 
wrote  twenty-one  scientific  papers  which   were 
published    in    journals    in    both    America    and 
Europe.  One  of  the  monuments  of  his  zealous 
work  were  the  470  species  of  fishes  which  he 
gathered,  described  and  drew  in  color  for  the  im- 
portant text  edited  by  Dr.  Albert  C.  L.  G.  Gun- 
ther.  The  Godeffroy  Museum  published  the  book, 
the  first  two  volumes  of  which  appeared  from 
1873  to  1875,  and  the  final  volume  of  which  was 
issued    in    1909,    twenty    years   after   Garrett's 

death.  This  production  remained  for  forty  years 
one  of  the  most  authoritative  publications  on 
fishes  of  Oceania.' 

Unfortunately  the  name  of  Andrew  Garrett  is 
virtually  forgotten,  except  by  a  few  experts.  Much 
of  Garrett's  important  pioneer  efforts  in  the  field 
of  marine  biology  were  published  by  other 
authors,  so  that  due  credit  was  not  always  given 
him.  Only  one  brief  obituary  was  printed 
simultaneously  in  several  scientific  journals  in 
America  and  England  a  few  months  after  his 
death.  A  short  outline  of  some  of  his  ac- 
complishments was  included  in  the  National 
Cyclopaedia  of  American  Biography  for  the  year 
1899  (vol.  2,  p.  162),  but  not  in  succeeding  editions 
or  in  similar  compilations  or  in  histories  of 
science.  For  many  years  his  name  and  accom- 
plishments were  omitted  from  print.  However,  in 

*  Part  2:  Catalogue  of  Molluscan  Species  and  Bibliograph.v  of 
Andrew  Garrett  by  William  J.  Clench  will  follow  in  the  next 
issue  of  The  Nautilus.  Manuscripts  submitted  November  It;. 

FIG.  1.  Andrew  Garrett  (1823-1887).  Fhntngraph  probably 
taken  in  Haivaii  about  1863.  Original  in  the  Museum  of  Com- 
ixirative  Zoology.  Harvard  College,  A/ass. 

16      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

the  last  twenty -five  years  there  have  been  several 
short  articles  about  him,  one  a  brief  chapter  in  a 
historical  treatise  on  early  scientific  collecting  in 
the  Pacific'  A  factor  which  may  account  for  the 
eclipse  of  Garrett's  reputation  after  his  death  was 
the  nonexistence  of  diaries  or  personal  papers.  In 
the  letters  from  him  which  do  exist,  he  seldom 
mentions  particulars  of  his  private  life.  Further- 
more, his   specimens   and   drawings   are   widely 
scattered  throughout  the  world  with  no  inventory 
of  his   scientific   collections   ever   having   been 
made.  Because  of  his  colorful  life  and  amazing 
travels   there   were   many   stories   and   possibly 
apocryphal  tales.  According  to  one  story,  Garrett 
had  a  mistress  established  on  each  of  the  islands 
where  he  periodically  visited  who  made  scientific 
collections  for  him  in  his  absence.  Another  story 
concerns  a  queen  of  a  remote  locality  where  he 
was  staying  who  induced  her  subjects  to  seize  a 
barrel  of  his  collecting  alcohol.  He  had  intended 
it  to  last  for  a  year  of  collecting  but  it  was  con- 
sumed in  one  evening's  drunken  orgy.  There  has 
been  no  way  of  substantiating  these  tales  as  they 
were  passed  down  by  word  of  mouth.  Furthermore, 
owing  to  gaps  in  our  information  as  to  Garrett's 
whereabouts    it    is    unlikely    that    a    definitive 
biogj-aphy  of  him  will  ever  be  written.  However,  the 
present  account  is  an  attempt  to  present  a  resume' 
of  the  information  that  can  be  documented. 

Early  Life 

This  pioneer  and  largely  self-trained  naturalist 
was  bjrn  in  Albany,  N.  Y.,  on  April  9,  1823.  He 
was  the  third  son  of  fourteen  children  and  spent 
part  of  his  early  youth  near  Middlebuiy.  Ver- 
mont. His  father,  Francis  Garrett,  was  a  native  of 
Canada;  his  mother,  born  Joanna  Campanaux, 
was  a  native  of  Belgium,  and  of  good  education. 
She  sp(jke  several  languages.  After  Andrew  left 
home  at  the  early  age  of  eleven,  his  family  moved 
to  Albany,  N.  Y.^ 

Early  in  his  life  young  Garrett  showed 
evidence  of  both  independence  and  scientific 
curiosity.  When  he  was  eight  years  old  he  left 
home  without  warning  to  visit  a  museum  one 
hundred  miles  away,  and,  then,  having  successful- 
ly completed  his  mi.ssion,  returned  safely.  When 
only  eleven  he  was  apprenticed  to  learn  the  trade 

of  an  iron  molder.  At  sixteen  he  abandoned  this 
vocation  and  went  to  sea  as  a  sailor  for  a  period 
of  three  years.  During  that  time,  according  to  his 
owTi  account,  he  touched  at  "nearly  all  the  West 
Indian  Islands,  the  Cape  Verde  Islands,  off  the 
African  coast,  as  well  as  the  Azores  and  Brazil 
and  several  Southern  States."  Reminiscing  on  this 
exploit  several  years  later,  he  wrote,  "I  now  went 
to  work  at  my  trade  again,  spending  my  leisure 
time  studying  the  plants  and  shells.  Still,  my  love 
of  seeing  new  countries  was  not  in  the  least 
abated  so  I  travelled  and  worked  (1842-1846)  in 
various  parts  of  the  Northern,  Middle  and 
Western  States."* 

After  these  wanderings  Andrew  determined  to 
go  abroad  again.  Meanwhile,  he  had  not  neglected 
his  interest  in  natural  history,  for  it  was  during 
this  time  of  roving  that  he  lingered  briefly  in 
Boston,  spending  happy  hours  in  the  museum  of 
the  Boston  Society  of  Natural  History.  "I 
wandered  about  the  suburbs  of  the  city  with 
Bigelow's  Flinri  B(if;t(inic))sis  in  my  hand,  study- 
ing plants.  Having  travelled  in  23  States  of  the 
Union,  I  concluded  to  go  abroad  again."* 

Pursuing  his  ambitions  Andrew  found  himself 
on  June  7,  1846,  signed  up  as  a  crew  member  of  a 
whaling  vessel  in  New  Bedford,  Massachusetts.  It 
was  the  bark  Edward,  bound  for  the  Pacific' 
Somewhere  in  the  early  course  of  this  voyage, 
Garrett  shipped  over  to  another  whaler,  the  Mza 
L.  B.  Jenney,  which  had  left  Fairhaven, 
Massachusetts,  on  November  30,  1846.  It  was 
fi'om  this  vessel  on  May  22,  1847,  that  Garrett 
stepped  ashore  at  the  busy  port  of  Honolulu.  The 
place  caught  his  fancy,  and  he  wrote  some  years 
later  that  he  was  so  much  pleased  with  its  ap- 
pearance that  he  made  up  his  mind  to  settle 
there.'  This,  indeed,  was  the  goal  he  achieved  five 
years  latei'. 

Within  a  day  or  two  of  Garrett's  arrival,  an 
American  missionary,  the  Reverend  S.  C.  Damon 
paid  a  visit  to  the  Jenney.  Damon  was  the  editor 
of  the  weekly  journal,  The  Friend,  dedicated  to 
the  spread  of  religion  among  seafaring  men.  Used 
to  boi.sterous  sailors  who  passed  through  the 
Hawaiian  Islands,  the  minister  was  charmed  by 
the  inquisitive  young  man  who  was  an  amateur 
scientist.   Such   a   vivid   impression   did   Garrett 

Vol.  93(1) 

January  10. 1979 

THE  NAUTILUS      17 

make  upon  the  older  man  that  eleven  years  after- 
wards, Damon  wrote;  "We  recollect  to  have  ac- 
companied him  to  the  forecastle,  and  beheld  with 
delight  the  collection  of  shells  which  he  had 
already  made.  In  reply  to  the  question,  'Why  did 
you  ship  before  the  mast?'  he  answered,  'In  order 
to  study  conchology.' "' 

That  extended  sea  voyage  marked  a  highlight 
in  the  life  of  the  young  sailor  not  only  because  of 
a  variety  of  adventures  but  also  the  experiences 
he  gained  in  e.xotic  and  faraway  localities.  These 
included  the  Marianas,  the  Bonins,  the  Ryukyu 
or  Liu  Chiu  Islands,  as  well  as  China,  the  Philip- 
pines, and  some  Australian  and  East  Indian 

When  Garrett  returned  with  his  vessel  on  May 
15,  1851,  to  its  home  port  of  Fairhaven,  adjacent 
to  New  Bedford,  he  must  have  gained  some 
satisfaction  as  the  yield  in  sperm  whale  oil 
from  this  voyage  amounted  to  '2,570  barrels.  That 
was  roughly  the  equivalent  of  $20,000.  Although 
Garrett  was  only  a  foremast  hand  on  a  whaling 
ship  his  share  must  have  been  considered  a  pro- 
fitable return  for  the  times.  But  even  more  im- 
portant to  him  were  the  twenty  packing  cases  of 
shell  specimens  which  he  had  assidiously  col- 
lected during  the  long  voyage.  He  himself  men- 
tioned this  success  six  years  after  the  incident 
when  he  was  corresponding  with  his  Boston 
patron,  James  M.  Barnard.  The  sailor-naturalist 
took  pains  to  mention  that  the  proprietor  of  a 
shell  store  on  State  Street  in  Boston  had  bought 
the  shells  as  well  as  some  of  the  skins  of  birds, 
specimens  of  fishes  and  Crustacea  which  he  had 

Ashore  in  Boston  in  the  spring  of  1851,  he 
seemed  uncertain  of  what  his  future  held.  He  was 
twenty -eight  and  he  had  behind  him  a  rather 
rough  and  wandering  life.  But  he  was  also  becom- 
ing more  and  more  engaged  in  the  study  of 
natural  history.  The  idea  of  sojourning  some- 
where in  the  Pacific  Ocean  and  perhaps  spend- 
ing his  life  there  must  have  been  in  his  thoughts. 
Even  six  years  before  when  his  whaling  ship  had 
touched  at  Honolulu,  he  wrote  he  had  been  so 
pleased  that,  "I  was  determined  to  settle  there"." 
During  the  next  year  or  so  after  his  return  he 
travelled  "through  most  of  the  States"  as  he  ex- 

pressed it,  perhaps  working  as  an  iron  molder. 
Finally,  he  left  California,  touching  briefly  at  Rio 
de  Janeiro  and  from  that  port  finally  headed  for 
the  Sandwich  Islands,  then  also  known  as  the 
Kingdom  of  Hawaii.  He  arrived  in  Honolulu 
sometime  in  the  spring  of  1852,  and  shortly 
thereafter  made  his  temjwrary  abode  on  the 
larger  island  of  Hawaii.  He  remained  there,  ex- 
cept for  various  collecting  trips  in  othei'  parts  of 
the  Pacific,  until  1863. 

In  the  Hawaiian  Islands 

Why  Garrett  selected  Hilo  to  be  his  headquarters 
will  probably  never  be  known.  Of  course,  it  was  one 
of  the  three  Sandwich  Island  ports  preferred  by  the 
captains  of  the  whaling  ships  from  the  1830's  until 
the  time  of  the  Civil  War,  when  the  whaling  in- 
dustry greatly  diminished. 

In  1850  the  total  population  of  the  five  islands  of 
the  Kingdom  of  Hawaii  was  only  84,165  in  contrast 
to  the  approximately  840,000  living  there  today. 
The  number  of  foreigners  was  only  1,962,  a  little 
over  2%.  These  persons  were  missionaries,  traders, 
plantation  owners,  and  others,  some  of  whom  had 
married  Hawaiians  and  occupied  government 
jxjsitions.  Others  were  members  of  the  diplomatic 
corps.  King  Kamehameha  III  was  in  the  twenty- 
seventh  year  of  his  reign.' 

Garrett  was  an  ardent  shell  collector  when  he 
arrived  in  Hawaii  in  1852  but  he  lacked  scientific 
training.  Doubtless,  it  was  his  association  with  a 
few  skilled  amateur  naturalists  which  influenced 
his  future  career  and  raised  the  level  of  his  in- 
terests above  those  of  the  mere  collector.  But,  being 
somewhat  quiet  and  shy  he  did  not  befriend  these 
persf^ns  at  once.  His  acquaintance  and  friendship 
with  the  avocational  scientists  of  the  Islands  seems 
to  have  come  about  gradually. 

Above  all,  it  must  have  been  the  richness  of 
nature  in  Hawaii  which  aroused  and  stimulated 
the  spirit  of  inquii7.  At  first  he  seems  to  have  been 
drifting  along  without  any  set  purpose.  We  do  not 
know  whether  or  not  he  had  some  occupation  or 
how  he  supported  himself  at  this  time.  However,  in 
the  fall  he  received  a  letter  from  Dr.  Wesley 
Newcomb,  an  American  physician  and  naturalist 
who  had  come  to  the  Islands  for  his  health. 
Newmmb  established  a  private  medical  practice 


January  10, 1979 

Vol.  93(1) 

and  eventually  became  government  Health  Officer, 
devoting  himself  on  the  side  t<^)  his  hobby  of  con- 
chology.  His  first  scientific  paper  on  land  shells  en- 
titled "New  Achatinclla"  was  published  by  the 
New  York  Lyceum  of  Natural  History  in  1853.  It  is 
known  that  Garrett  collected  for  Newcomb  and 
within  a  year  the  doctor  was  proposing  to  name  a 
new  species  of  shell  in  honor  of  his  friend,  writing, 
"It  would  afford  me  much  pleasure  to  embalm  your 
name  not  your  person,  to  have  it  associated  with  a 
fine,  new  species  from  Hawaii.  When  this  is  fixed, 
it  descends  through  all  coming  time."' 

At  this  time  in  Honolulu  there  was  considerable 
interest  in  collecting  shells,  both  local  specimens 
and  those  from  foreign  shores.  The  comings  and 
goings  of  sea  captains  and  sailors,  traders  and 
missionaries  probably  had  stimulated  this  traffic. 
The  great  abundance  of  tree  snails  with  their 
bright  colors,  gathered  by  the  native  Hawaiians, 
was  another  form  of  trade.  There  was  even  a  shell 
store  in  Honolulu  from  about  1852  to  1858,  main- 
tained by  Dominique  Frick,  who  had  once  been  the 
French  consular  agent.' 

We  know  that  Newcomb  left  for  the  United 
States  in  March,  1855,  but  we  do  not  know  much 
about  Garrett's  association  with  other  naturalists, 
e.xcept  that  he  was  collecting  and  had  access  to  a 
limited  amount  of  literature  and  at  the  same  time 
was  teaching  himself  to  draw  and  paint.  It  may 
have  been  due  to  loneliness  but  also  due  to  his 
aspirations  of  becoming  a  professional  collector 
that  Garrett  on  January  29,  1855,  wrote  a  letter  to 
one  of  the  most  distinguished  scientists  of  his  day. 
He  addressed  it  to  Prof.  Louis  Agassiz  who  had 
recently  arrived  in  the  United  States  as  lecturer  at 
Harvard  and  who,  anxious  to  build  up  a  core  of 
collectors  throughout  the  world,  had  issued  some 
printed  literature  soliciting  contributions.  Garrett 
included  sample  drawings  of  fishes  and  some  in- 
vertebrates, explaining  he  would  continue  to  make 
sketches...  "so  that  in  the  event  of  your  observing 
any  new  species,  or  such  as  you  would  like 
specimens  of,  you  can  inform  me.  .  .  I  do  not  make 
any  pretensions  to  a  knowledge  of  Ichthyology.  .  . 
yet  will  endeavor  to  write  a  description  of  each." 
He  continued  that  he  would  be  glad  to  exchange 
specimens  in  any  branches  of  natural  history  and 
desired  in  return  either  specimens  of  shells  new  to 

him  or  copies  of  such  books  as  Storer's  Fishes  of 
Massachusetts  or  of  Dr.  Gould's  books  on  shells.'" 
Although  the  financial  resources  of  Harvard 
University  were  at  a  low  ebb,  a  very  fortunate 
arrangement  was  made  through  Agassiz's  Boston 
friend,  the  merchant  and  shell  collector,  James  M. 

By  September,  1856,  almost  seventeen  months 
later,  Garrett  received  a  reply  to  his  inquiry  to 
Professor  Agassiz.  It  was  from  Mr.  Barnard,  writ- 
ten on  the  professor's  behalf,  inviting  young 
Garrett  to  become  a  zoological  collector  on  a  per- 
manent basis.  Garrett  replied  that  he  was  most 
happy  to  do  so  as  he  had  no  regular  employment 
and  was  on  the  point  of  returning  to  the  United 
States.  In  his  letter  of  acceptance,  he  concluded  to 
charge  $400  per  year  which  would  cover  all  of  his 
traveling  expenses,  food,  hiring  of  assistants,  his 
own  salary  and  would  further  enable  him  to  go  on 
various  ships  to  remote  islands." 

The  impetus  furnished  by  Louis  Agassiz  for  him 
to  apply  and  improve  his  already  self-acquired 
scientific  techniques  of  observing,  collecting  and 
recording  came  to  Garrett  at  what  seems  an  ap- 
propriate time.  On  December  1,  1856,  at  Hilo  he 
shipped  aboard  the  whaleship,  Lydia,  whose  master 
was  John  W.  Leonard.  Considering  the  territoiy 
covered  in  the  voyage  which  included  the  Society 
Islands  and  some  of  the  Marquesas  Islands,  the 
vessel  was  away  from  Hawaii  for  the  surprisingly 
short  span  of  three  months.  The  voyage  was  highly 
.successful  from  the  point  of  view  of  the  variety  and 
number  of  specimens  gathered,  but  a  tragic  event 
came  later.  After  the  reshipment  of  the  rollections 
to  another  vessel,  the  Joh))  Gilpin,  the  latter  vessel 
was  wrecked  on  its  return  to  the  United  States  in 
November,  1857,  and  its  cargo  lost,  which  included 
considerable  but  not  all  the  material  destined  for 
Harvard.'^  It  happened  there  were  duplicates 
retained  by  Garrett  and  some  of  the  fish  pictures 
were  already  in  the  possession  of  Captain  Leonard 
who  eventually  reached  home  safely. 

Recently,  through  the  courtesy  of  Barbara  John- 
son of  Princeton,  an  interesting  letter  from 
Leonard  to  his  wife,  Lydia,  has  come  to  light.  It 
provides  confirmation  that  the  American 
naturalist  was  making  fish  pictures  specifically  for 
Captain  I^eonard.  In  part,  I^onard  s;iid,  "Since  I 

Vol.  93(1) 

January  10, 1979 

THE  NAUTILUS      19 

wrote  last  we  have  passed  through  several  stirring 
adventures  (new).  We  have  been  at  Fannings 
Island,  and  Mitui,  one  of  the  lower  archipelagos. 
And,  also  at  the  Island  of  Huehine  [sic]  where  we 
have  gathered  a  splendid  lot  of  shells  and  fishes. 
We  have  a  naturalist  (Garrett)  as  Passenger  with 
us  which  makes  it  very  pleasant.  And  he  is  painting 
a  fine  lot  of  Fish  for  me  and  collecting  a  beautiful 
lot  of  shells.  So  I  shall  have  a  fine  Colection  [sic] 
when  I  get  Home.""  Of  course,  the  principal 
benefactor  was  Harvard  College  and  its  museum  of 
natural  history.  Later,  most  of  this  material  was 
described  and  pictured  in  the  publication  of  the 
Godeffroy  Museum  of  Hamburg. 

We  have  in  this  statement  Leonard's 
corroboration  of  the  fact  that  part  of  this  was  the 
same  collection  of  watercolor  drawings,  all  drawn 
by  Garrett,  which  survived  in  the  family  of  John 
Leonard's  descendants.  They  are  now  the  property 
of  the  author  of  this  article.  A  further  item  of  in- 
terest is  that  the  Leonard  set  contains  a  Garrett 
picture  of  a  beautiful  wrasse  fish  of  the  family 
Labridae  which  the  artist -scientist  named  Julis 
leonardianum  undoubtedly  in  honor  of  his  whaler 

A  few  months  after  Garrett  returned  from  his 
voyage  to  Hawaii,  he  received  a  four-page  letter  in 
the  handwriting  of  Professor  Agassiz,  addressed  to 
John  M.  Barnard  but  intended  for  the  naturalist- 
employee.  It  has  significance,  for  it  served  as  a 
guide  for  proper  collecting  and  scientific  ob- 
servation. A  total  of  three  such  letters  from  Agassiz 
composed  for  Garrett's  benefit  still  exist  and  are 
preserved  in  the  library  of  the  Bishop  Museum  in 
Honolulu.  The  first  one,  dated  August  28,  1857,  ex- 

"The  principal  merit  of  collections  of  objects  of 
nature  is  not  desired  in  our  days  from  the  ac- 
cidental circumstances  that  they  may  contain  new 
species  but  from  the  opportunity  they  afford  of 
elucidating  natural  laws.  The  collector  ought, 
therefore  to  have  his  attention  constantly  turned  to 
this  important  end  and  must  on  that  account 
collect  in  a  particular  way. . .'" 

He  went  on  to  e.xplain  that  large  quantities  of 
specimens  of  one  species  in  all  sizes  should  be  ob- 
tained as  they  all  afford  the  means  of  ascertaining 
the  range  of  different  species.  He  added  that  the 

slightest  difference  between  specimens  of  adjoining 
localities  should  be  taken  into  account.  Even  in  the 
case  of  adjoining  islands  "or  opposite  shores  of  the 
same  island  specimens  must  be  collected  of 
everything.  .  .  It  is  thus  ascertained  that  the  dif- 
ferent groups  of  Islands  of  the  Pacific  may  be 
inhabited  by  distinct  representatives  but  identity 
nuist  be  made  out  by  direct  comparison  and  can 
neither  be  assumed  or  denied  before  hand". 

Meanwhile,  the  instructions  Garrett  had  re- 
ceived for  collecting  and  his  own  zeal  compelled 
him  to  adopt  and  use  more  precise  methods. 
Through  a  letter  to  Barnard,  written  after  the  trip 
on  the  Lydia.  he  reported  on  his  field  collecting.  He 
explained  that  he  made  it  a  point  to  gather  those 
specimens  which  did  not  often  occur.  "When 
searching  along  the  coast  I  have  to  take  pencil  and 
paper,  an  assortment  of  small  jars,  boxes  and 
calabashes  which  my  native  boys  carry.  And  when  I 
find  anything  I  which  to  preserve  I  first  note  the 
depth  of  water,  kind  of  bottom,  its  mode  of 
locomotion  and  colors  while  alive.  And  I  find  it 
necessary  to  preserve  them  in  water  while  carrying 
them  about  so  that  their  delicate  parts  will  remain 
perfect  until  I  can  place  them  in  alcohol."  He  said 
that  he  found  it  essential  to  make  rough  sketches  of 
many  objects  in  order  to  give  a  clear  idea  of  their 
markings.  He,  also,  added  that  he  had  his  own 
catalogue  of  the  crustaceans  in  which  he  recorded 
everything  relative  to  each  species  which  he 
found.'*  It  so  happened  that  at  the  time  Garrett 
mentioned  his  misgivings  as  a  scientific  field 
worker.  Professor  Agassiz  had  time  to  examine 
some  of  the  young  worker's  drawings.  In  an  un- 
dated letter  to  J.  M.  Barnard,  probably  written  in 
the  fall  of  1857,  he  said  "I  have  been  much  pleased 
with  the  drawings  as  well  as  the  descriptions  of  Mr. 
Garrett.  They  will  be  invaluable  material  to  clear 
up  the  Natural  History  of  the  Pacific  Ocean  but  I 
would  warn  him  not  to  be  hasty  in  publishing 

Relationship  with 
William  Harper  Pease 

William  Harper  Pease  (1824-1871),  surveyor 
and  conchologist,  reached  Hawaii  when  he  was 
twenty-five  years  old.  He  had  travelled  in  Mexico 
with  General  Scott's  army  and  had  made  extensive 

20      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

collections  there  of  birds,  insects  and  other  fauna 
for  the  Academy  of  Natural  Sciences  of  Philadel- 
phia. Even  at  that  early  age,  he  had  already  pub- 
lished the  first  of  his  scientific  papers  which 
totalled  82  articles  by  the  time  of  his  death.  Pease  to  be  in  Hawaii  for  reasons  of  health,  reach- 
ing there  in  1849  and  residing  in  Honolulu  until  his 
demise  in  1871.  In  a  short  time  he  became  an  im- 
portant man  with  interests  enabling  him  to  travel 
through  the  islands.  He  worked  as  a  land  surveyor, 
and  held  the  position  of  Assessor  of  the  City  of 
Honolulu  as  well  as  being  Commissioner  of  Water 
Rights.  But,  preeminently  he  was  a  scientist. 
Like  Garrett  he  was  a  self-taught  naturalist  but  by 
the  time  they  met.  Pease  had  acquired  the  dis- 
ciplines of  scientific  research  and  was  an  inveterate 
collector.  Pease  helped  Garrett  not  only  by  engag- 
ing him  as  his  principal  collector  but  allowing  his 
friend  to  use  his  conchological  and  scientific  books, 
instructing  him  in  method  of  research  and  in  other 
ways.  It  is  very  fortunate  that  there  was  such  a 
person  available  to  Garrett  for  his  guidance  and 
stimulation,  and  as  the  two  first  met  in  1857,  in  a 
sense  Pease  took  the  place  of  Newcomb  who  left  the 
Islands  in  18.56,  and  had  formerly  been  the  young 
collector's  friend  and  mentor. 

For  six  yeai"s  despite  the  various  absences  of 
Garrett  on  collecting  trips,  they  saw  each  other 
fairly  frequently.  After  the  summer  of  1863, 
Garrett  left  Hawaii  never  to  return  before  Pease's 
death  in  1871.  but  they  kept  up  a  faithful 
correspondence.  A  group  of  letters  from  Pease  to 
Gari'ett  written  during  the  whole  period  of  their 
fiiendship  (1857-1871)  sun-ives  in  Honolulu's 
Bishop  Museum.  Excerj^ts  from  them  are  given  in 
the  series  of  articles  by  Karl  W.  Green  published  in 
I960."  and  others  were  quoted  in  the  biography  of 
Pease  by  Dr.  E.  Allison  Kay.'  The  relations  of  these 
two  men  was  friendly,  although  Pease  took  almost 
a  paternalistic  attitude  toward  Garrett.  There  was 
a  difficult  side  for  Garrett.  It  is  true  that,  in  a 
sense,  he  was  an  employee  of  the  other  man,  but  in 
some  ways  Pease  seems  to  have  taken  advantage  of 
Garrett's  abilities  and  efforts.  The  latter  worked 
hard  and  laboriously.  He  collected  amid  the  most 
trying  and  dangerous  conditions.  He  scrupulously 
described  and  drew  pictures  of  many  of  the 
specimens  gathered,  particularly  the  fishes.  In  the 

case  of  fishes  and  shells  he  suggested  the  scientific 
names.  But  despite  all  this,  he  lived  in  the  shadow 
of  Pease  while  the  more  articulate  writer  and  more 
assertive  man  earned  the  glory. 

Collecting  in  the  Kingsmill  Islands 

Was  it  restlessness  or  a  desire  to  form  collections 
ft-om  le.sser  known  areas  that  goaded  Garrett  to 
make  so  many  scientific  forays?  We  sense  that  the 
business  arrangement  with  the  museum  at  Har- 
vard as  well  as  the  enthusiasm  of  both  Professor 
Louis  Agassiz  and  the  Boston  businessman  James 
M.  Barnard,  must  have  been  the  stimulants  to  these 
persistent  travels. 

Hawaii  was  a  focal  point  from  which  trading 
schooners  and  whaling  ships,  served  as  a  means  of 
transportation.  One  of  the  latter  was  the  brig,  Mar- 
ni)i(]  Star,  operated  by  the  Board  of  Missions  to  con- 
vey American  missionaries  and  their  trained 
Hawaiian  assistants  to  the  various,  far-flung  island 
stations."  These  mission  voyages  were  financed  by 
sums  of  money  raised,  largely  by  New  England 
school  children.  Garrett  explained  that  he  had 
made  reasonable  arrangements  as  a  passanger 
aboard  the  Moi-ning  Star  paying  $1.50  per  day 
while  he  stayed  on  board,  with  an  additional  charge 
for  his  package  of  specimens.  A  plan  developed  so 
that  he  could  sail  directly  to  one  of  the  islands  and 
stay  there  collecting  for  three  months." 

Our  conchologist  carried  complete  provisions  as 
well  as  articles  of  trade  to  last  him  at  least  four 
months.  The  materials  included  cutlery,  edge  tools, 
beads,  calico  cloth  and  even  400  board  feet  of  lum- 
ber with  which  to  build  wooden  boxes  for  the 
return  of  his  specimens.  The  brig,  Morning  Star, 
left  Hawaii  on  August  11,  1859,  but  due  to  adverse 
winds  and  currents  took  longer  for  the  trip  to  the 
South  Pacific  than  would  ordinarily  be  the  case. 
Finally,  after  a  voyage  of  three  weeks  from 
Honolulu,  the  two-masted  vessel  reached  its 
destination  on  September  9th.  This  was  Apiang, 
one  of  the  northern  islands  of  what  are  now  known 
as  the  Gilberts  in  Micronesia.  It  must  have  been  a 
strange,  remote  place,  being  flat  and  palm-covered 
coral  rock.  It  was  about  fifteen  miles  square  and 
had  a  total  of  not  over  300  to  400  inhabitants,  living 
in  small,  scattered  villages.  While  the  Rev.  and 
Mrs.  Hiram  Bingham,  who  ran  the  mission,  lived 

Vol.  93(1) 

January  lU,  1979 

THE  NAUTILUS      21 

near  their  thatched  church  a  scant  distance  away, 
Garrett  established  himself  in  a  rather  flimsy, 
borrowed  dwelling.  With  the  limited  help  of  his 
servant  Temawa,  the  naturalist  busied  himself  in 
making  e.xtensive  collections.  To  do  this  he  daily 
waded  for  long  hours  over  the  inner  and  outer  plat- 
forms of  the  nearby  lagoons.  He  also  exchanged 
small  bits  of  his  trade  goods  for  selected  specimens 
of  fish,  shells,  echinoderms,  and  other  forms  of 
aquatic  life.  Several  dozen  natives  crowded  around 
him  almost  every  hour  of  the  day,  causing  him  end- 
less misery.  This  slowed  down  his  work  of 
preparing  specimens,  making  drawings  and  jotting 
down  notes.  Their  repeated  attempts  to  steal  his 
belongings  made  him  worn,'  that  they  might  seize 
and  drink  the  precious  preserving  alcohol,  so  that 
he  frequently  worked  into  the  late  hours  of  the 
night  when  his  unwelrome  guests  were  not  around. 
After  some  days  of  deceiving  the  natives  about  the 
alcohol,  they  detected  its  smell.  They  would  have 
taken  it  from  him  had  he  not  convinced  them  that 
it  was  poisonous  type  of  substance.  Another 
nuisance  he  had  to  bear  were  visits  by  inhabitants 
of  other  islands.  All  of  them  demanded  to  see  and 
handle  what  they  called  his  "wonders".  These  were 
a  mechanical  music  box,  a  magnifier  with  mirror, 
and  the  "plates"  or  pictures  of  natural  history  sub- 
jects which  he  had  brought  with  him  or  had  done  on 
the  spot.  Although  his  companions  demanded  that 
he  buy  all  their  zoological  specimens  they  brought 
to  him  in  large  quantities,  he  found  it  judicious  to 
acquire  only  a  few  representative  ones  from  each 
lot  so  as  not  to  discourage  the  vendors  from  con- 
tinuing to  collect  for  him.  Lacking  a  knowledge  of 
the  language,  he  was  compelled  to  use  pantomime 
combined  with  mixed  words  of  Hawaiian  and 
English,  but  seemed  to  succeed  fairly  well  in  com- 
municating. Unfortunately,  at  frequent  intervals 
he  was  ill  with  fever  or  other  complaints  and  when 
attempting  to  rest,  found:  "a  pair  of  black  eyes 
glistening  at  every  crevice  in  sides  of  the  house." 
Sometimes,  due  to  the  crowds  of  noisy  visitors,  for- 
ty or  fifty  in  a  group,  he  had  to  close  up  his  house 
and  take  long  walks  to  get  away  from  the  tumult." 

From  time  to  time  the  busy  collector  had  some 
contact  with  the  ruler.  King  Tekaiia.  This  person 
did  not  seem  to  be  a  real  monarch.  Garrett 
described  him  as  a  large,  corpulent  man  whose  only 

clothing  was  a  rough  mat  of  leaves  wrapped  around 
his  loins.  He  lacked  the  respect  of  his  subjects  who 
seemed  to  ignore  his  authority.  When  one  day 
several  unfamiliar  natives  arrived  from  the  nearby 
Island  of  Maraki,  Garrett  noticed  that  they  were 
"bringing  with  them  several  Kanaka  heads.  They 
stated  that  there  had  been  a  battle. . .  and  the  heads 
were  those  of  some  of  their  friends  who  had  been 
slain  and  they  had  cut  them  offf  and  fled  to  prevent 
them  (the  heads)  from  falling  into  the  hands  of  the 
enemy."  One  detects  a  note  of  reprovement  in  our 
traveler's  remarks  on  his  observations  of  the 
Micronesian  Christian  converts.  They  often  dozed 
during  the  sermons  of  the  missionaries  or  plucked 
and  ate  the  lice  from  each  other's  heads  while  at- 
tending church.  He  was  further  shocked  when  one 
day  in  passing  the  council  house  he  was  overcome 
by  the  stench  from  a  putrid  corpse.  It  was  the  body 
of  an  elderly  and  venerated  chief  whose  funeral  ser- 
vices extended  over  several  days. 

Despite  the  hard  times  and  vicissitudes  which 
the  naturalist  had  to  endure,  one  realizes  from  his 
journal  how  enthusiastic  and  excited  he  became 
when  he  encountered  new  species  of  shells  and  fish. 
On  its  return  from  Apiang  with  Garrett  and  his 
booty  aboard,  his  ship  stopped  at  Ebon  Island 
where  he  acquired  additional  specimens.  When  he 
arrived  back  in  Hawaii  on  January  11.  1860,  he 
must  have  had  considerable  satisfaction  in  the  suc- 
cess of  the  expedition.  A  record  of  the  importance 
of  the  venture  is  also  incorporated  in  the  official 
report  of  the  Harvard  Museum  quoting  Agassiz  on 
the  acquisitions  from  the  Pacific  Ocean,  which 
stated,  "the  total  number  of  specimens  of  fishes 
amounts  to  five  thousand,  comprising  1.000  dif- 
ferent species,  the  most  important  of  which  are 
from  the  Kingsmill  and  Society  Islands,  collected 
by  Mr.  Garrett"^"  Despite  this  account  it  is  quite 
likely  there  was  an  error  in  the  report  as  the  collec- 
tions noted  probably  included  shells  and  other 
organisms  in  addition  to  fishes. 

Second  Visit  to  the  Society  Islands 

It  is  unfortunate  that  there  is  such  scant  in- 
formation about  Garrett's  second  visit  to  the 
Society  Islands  which  took  place  from  1860  to  1863. 
The  Society  Islands  offered  ample  opportunities  for 
new  discoveries,  despite  the  collections  of  Captain 

22      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

James  Cook's  associates,  Lesson,  Hugh  Cuming, 
and  otliers.  Commenting  on  the  early  work  of  these 
scientists,  Garrett,  writing  some  twenty  years  later 
in  his  own  research  article,  remarked  "During  the 
years  1860-1863  I  made  a  much  more  thorough  ex- 
ploration (of  land  shells)  than  any  of  my 
predecessors,  and  by  searching  in  nearly  every 
valley  of  the  group,  discovered  50  new  species. .  ."^' 
He  left  Hawaii  for  Tahiti  and  the  other  islands  in 
May,  1860."  The  manner  of  life  of  the  natives  there 
had  probably  not  changed  appreciably  since  his 
visit  of  three  years  previously  when  he  observed, ". . 
conditions  being  there  the  same  as  at  the  Sandwich 
(Hawaiian)  islands  in  the  form  of  indolence, 
drunkeness,  and  the  most  loathsome  diseases  which 
he  felt  were  rapidly  decimating  the  population.  I 
cannot  perceive  as  they  have  improved  an  iota  in 
there  moral  or  physical  condition  notwithstanding 
40  years  of  missionary  labor  and  intercourse  with 

More  importantly,  he  wrote  of  the  marked 
similarity  in  the  marine  fauna  in  French  Pol>Tiesia 
in  comparison  with  that  in  the  Sandwich  Islands. 
Though  the  natives  of  each  island  group  spoke  a  dif- 
ferent language,  they  used  the  same  name  for  the 
same  objects  common  to  both  areas.  He  noted  that 
residents  of  Boston,  New  York  and  Baltimore  had 
two  or  three  names  for  the  same  natural  species. 
Still  he  found  natives  living  2,000  miles  away  from 
one  another  speaking  almost  a  different  tongue  but 
using  the  same  name  for  the  same  species  of  fish. 
"All  Polynesian  Islanders  have  with  very  few  ex- 
ceptions a  distinct  name  for  ever>'  kind  of  animal, 
plant  and  mineral,  no  matter  how  small  and  ob- 
scure the  object  is."  He  concluded  by  saying  "They 
as  a  mass  have  a  better  knowledge  of  the  natural 
productions  of  the  islands  than  the  mass  of  people 
in  the  United  States"." 

Although  we  have  so  little  information  about 
Garrett  on  this  particular  Society  Island  sojourn, 
we  do  find  a  reflection  of  his  interests  in  the  letters 
Pease  wrote  him  and  which  he  so  carefully  kept.  On 
September  2,  1860,  Pease  wrote  proposing  their 
collaboration  on  a  series  of  popular  natural  history 
publications  which  would  contain  lithographs  of 
the  watercolor  drawings  as  well  as  printed  descrip- 
tions of  the  more  common  fishes,  shells  and  plants. 
"My  opinion   is  the  most  effectual   mode  is  to 

publish  a  small  pamphlet  in  numbers,  similar  to 
those  of  Professor  Adams,  'Contributions  to  Con- 
cholog>''.  I  think  I  shall  issue  one  before  you 
return."  Pease  went  on  to  explain  that  the 
publication  would  contain  "your  descriptions  of 
fishes  and  a  portion  of  the  descriptions  of  shells  I 
have  forwarded  to  Cumings.""  It  is  quite  likely 
that  a  series  of  30  handwritten  sheets  of  descrip- 
tions of  fishes  and  shells  of  both  Hawaii  and  the 
Society  Islands  in  Garrett's  handwriting  with  bor- 
ders drawn  around  them,  each  with  a  watercolor 
drawing,  are  part  of  the  group  previously  men- 
tioned as  now  owned  by  the  author  were  intended 
for  the  pamphlet.  Unfortunately,  the  projected 
publication  never  appeared  as  far  as  is  known. 

In  the  Central  Pacific  (1863-69) 

Apparently  Garrett  returned  from  his  Society 
Island  explorations  about  July,  1863.  The  months 
that  followed  were  crucial  ones  as  he  decided  to 
abandon  his  base  in  Hawaii  and  go  off  on  even  more 
extensive  voyages.  In  welcoming  him  back  to 
Honolulu,  the  Rev.  Samuel  C.  Damon,  reporting  en- 
thusiastically of  the  naturalist's  accomplishments, 
wrote  ".  .  .  he  has  visited  every  island  and  every 
valley  and  reef  of  every  island,  collecting  specimens 
of  shells,  fishes  and  every  variety  of  animal  and  in- 
sect. The  extent  of  his  collections  may  be  indicated 
by  the  fact  he  has  used  three  hundred  gallons  of 
alcohol  in  preserving  the  specimens.  He  has  col- 
lected 400  different  species  of  fishes.  Each  one  of 
these  is  beautifully  painted  from  life.  Some  of  his 
drawings  which  we  examined  are  executed  with 
great  skill  and  taste.  The  number  of  these 
specimens  which  were  forwarded  from  the  Society 
Islands  would  not  fall  below  ten  thousand. "^^ 

With  his  long  journey  behind  him  and  with  his 
collections  shipped  away,  he  had  to  put  off  the  blan- 
dishments of  his  friend  Pease.  The  latter  was  in- 
sisting that  he  remain  and  help  with  his  projected 
commitments  for  publication.  In  fact.  Pease  at  this 
time  was  writing  several  papers  on  land  shells 
probably  based  in  part  on  Garrett's  collections. 
Eight  papers  appeared,  chiefly  on  this  topic,  with 
Pease's  name  attached  in  the  Proceedings  of  the 
Zoological  Society  of  London  between  1864  and 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      23 

Garrett,  making  preparations  for  his  next  ex- 
tended voyage,  received  a  letter  dated  October  from 
his  San  Francisco  agent,  Sam  Hubbard.  He  had 
purchased  for  him  a  supply  of  alcohol,  a  music  box 
with  which  to  entertain  the  natives,  a  magnetic 
machine  (which  may  have  been  a  surveying  instru- 
ment), and  a  series  of  other  articles.  The  most 
expensive  item  was  a  complete  wet  plate  photo- 
graphic apparatus  which  included  a  camera,  plates 
and  chemicals.  It  cost  $376.76,  an  enormous  sum, 
considering  that  Garrett's  yearly  salary  was  only 

Another  important  activity  for  Garrett  in  his 
1863  stay  in  Hawaii  was  identifying  both  shells 
and  fishes  for  the  California  Academy  of  Sciences. 
That  institution  had  made  him  a  corresponding 
member  in  1856  and  its  Proceedirujs  in  1857  had 
carried  his  article  on  marine  shells,  probably  his 
first  scientific  contribution  to  be  printed.^  That 
same  organization,  hearing  of  his  new  expedition, 
sent  him  twenty  gallons  of  preserving  alcohol 
which  they  said  was  to  be  used  "according  to  your 
best  judgment,  taking  sufficient  of  it  to  reimburse 

Meanwhile,  in  August,  Damon,  in  the  same  letter 
referred  to,  outlined  the  extensive  South  Sea 
Islands  voyage  the  conchologist  was  planning.  It 
would  include  the  Marquesas  Islands,  the  Naviga- 
tors (Samoa),  Friendly  (Cook)  and  the  Fiji  Island 
groups.  This  would  be  a  period  of  no  less  than  five 
or  six  years  which  he  would  devote  to  new  ex- 
plorations. Damon  added,  ". .  .he  is  perfecting  him- 
self in  the  photographic  art,  as  he  will  go  prepared 
to  take  views  of  natural  scenery,  animals  and  the 
inhabitants  of  those  remote  regions.  Hereafter,  his 
researches  will  embrace  a  wider  range  than  they 
have  hitherto  done." 

Late  in  1863  Garrett  got  off  but  we  have  only  a 
vague  knowledge  of  his  specific  locations  in  the 
next  six  years.  He  chose  for  his  collecting  grounds 
two  main  areas  2,000  miles  and  more  south  of  his 
former  haunts  in  the  Hawaiian  Islands.  These 
were,  first,  the  Tuamotu  Islands,  a  large  ar- 
chipelago, stretching  from  140°  to  150°  West 
Latitude  and  situated  east  of  the  Society  Islands. 
He  seems  to  have  been  there  for  most  of  1864  and 
1865  but  we  have  no  records  of  the  precise  places  of 
his  collecting.  For  the  second  part  of  his  travels,  he 

was  in  the  Cook  Islands,  Western  Samoa  and,  then 
for  a  good  part  of  1867  to  1869  he  moved  about  the 
Cook  Islands. 

Garrett  was  not  only  doing  his  usual  collecting 
but  was  also  taking  photographs  of  the  native 
people.  We  have  already  noted  his  purchase  of  a 
camera  and  the  necessary  equipment.  On  Januar>' 
20,  1864,  not  long  after  his  departure  from  the 
Hawaiian  Islands,  Pease  wrote  to  him  ".  .  .  Not  a 
day  passes  without  my  dreaming  of  your  fortune 
and  success.  I  have  imagined  the  missionaries 
might  decide  that  your  photographs  were  a  useless 
article  of  furniture  and  discourage  the  natives  from 
patronizing  you,  and  then  again  I  think  I  see  you 
surrounded  by  a  crowd  of  natives,  dancing  and 
shouting  with  the  pictures.  I  shall  be  anxious  to 
receive  your  first  letter."" 

During  the  period  1863  to  1866,  according  to  a 
recent  writer,  Pease  continued  to  sponsor  Garrett's 
trips  at  least  in  part  and  continued  to  act  as  his 
agent  in  Honolulu.  Garrett  sent  Pease  descriptions 
of  his  living  specimens  and  drawings  of  shells  and 
nudibranchs  for  inclusion  in  the  numerous  papers 
Pease  was  writing.' 

It  cannot  be  accurately  determined  when  Garrett 
ceased  his  activities  on  behalf  of  Harvard's  musuem 
but  it  was  sometime  around  1863.  Agassiz  was 
having  financial  troubles  at  this  time.  Another 
factor  could  have  been  unfavorable  circumstances 
brought  on  by  the  Civil  War  or  other  reasons  which 
might  have  terminated  James  M.  Barnard's  annual 
payment  of  his  salary.  Certainly,  the  slacking  off  of 
American  vessels  engaged  in  the  whaling  industry 
all  over  the  world  may  have  been  a  contributing 
cause.  Some  of  these  vessels  had  been  acquired  by 
the  Federal  Government  to  be  taken  south  and 
sunk  to  block  up  shipping  in  southern  coastal  ports, 
while  others  which  were  already  at  sea  at  the  out- 
break of  hostilities  were  captured  or  destroyed  by 
the  Confederate  Navy. 

Garrett  and  the  Godeffroy  Museum 

These  circumstances  may  well  have  helped  bring 
about  Garrett's  affiliation  with  another 
organization.  Ever  since  the  early  19th  century  an 
important  shipping  and  trading  company  of  Ham- 
burg had  operated  vessels  between  Germany  and 
South  America's  west  coast.  This  was  the  firm  of  J. 

24      THE  NAUTILUS 

Januao'  10. 1979 

Vol.  93(1) 

C.  Godeffroy  and  Son,  which  after  having  suc- 
ces-sfully  managed  a  fleet  of  cargo-carrying 
passenger  ships  to  South  America,  Australia  and 
California,  found  its  business  cut  off  after  1855.  In 
that  year  one  of  its  representatives,  August  Un- 
shelm,  had  been  following  orders  seeking  out 
business  possibilities  of  trade  for  native  products  in 
such  Pacific  islands  as  the  Carolines,  the  navigators 
(Samoa),  the  Friendly  (Cook  Islands)  and  the  Fiji 
Islands.  As  a  permanent  headquarters  and  trading 
station  for  the  whole  area  the  firm  purchased  land 
at  Apia,  Samoa.  For  the  next  twelve  years  this 
grew  into  an  impressive  establishment  with  its  own 
plantations  of  coconuts  and  cotton  and  a  trading 
center  serving  several  large  clusters  of  remote 
islands.  By  1864,  a  new  Godeffroy  employee,  young 
Theodore  Weber,  took  over  as  head  of  the  business 
at  Apia.  He  acquired  more  land  and  directed  the 
production  of  copra  which  after  its  arrival  in 
Europe  was  processed  into  candles  and  soap.^ 

Meanwhile,  back  in  Hamburg,  Johann  Caesar 
Godeffroy,  head  of  the  firm,  had  a  museum  to  house 
exhibits  of  rare  material  of  the  Pacific  Islands  in 
the  fields  of  anthropology  and  zoology.  He  had 
hired  a  young  Swiss  zoologist,  Dr.  Edward  Graeffe, 
to  set  up  and  display  the  collections  which  were 
being  supplied  by  the  captains  of  his  twenty  dif- 
ferent vessels  then  travelling  back  and  forth  bet- 
ween Hamburg  and  Oceania.  They  had  special  in- 
structions to  secure  natural  history  specimens  and 
native  artifacts.  A  year  later,  J.  D.  E.  Schmelz,  a 
qualified  scientist,  became  custodian  when  Godef- 
froy sent  Dr.  Graeffe  out  to  Samoa  and  Tahiti  on  a 
ten  year  assignment  as  collector  for  the  new  in- 
stitution. Simultaneously,  the  Musuem  sent  a  small 

band  of  collector-scientists  into  the  field.  Garrett 
became  one  of  these  about  two  years  later." 

By  1866  Garrett  was  established  in  Samoa  and 
busy  collecting  on  the  Islands  of  Upolo  and  Savaii. 
His  name  had  been  known  previously  in  Hamburg, 
as  some  of  the  shells  he  gathered  were  sold  to  the 
Hamburg  government  museum  in  1862.  About  this 
time  at  Apia  he  came  into  the  good  graces  of  the 
Godeffroy  representative,  Weber,  and  in  1866  the 
American  had  obtained  passage  on  the  company's 
ship  the  Alfred  which  transported  him  to  the  Fijis. 
The  agent  reported  this  in  a  letter  to  his  employer 
sent  from  Samoa  August  17,  1866,  requesting  that 
Garrett  be  permanently  engaged.  Godeffroy  ap- 
proved this  recommendation  and  authorized 
Garrett  to  gather  zoological  specimens.  Godeffroy 
promised  to  send  the  needed  supplies  for  collecting 
and  preserving.  Garrett  was  to  receive  five  hundred 
Chilean  pesos  for  the  first  year,  as  well  as  free 
passage  in  the  company  ships  and  to  be  treated 
"always  in  the  kindest  way  possible."  In  return  for 
the  payment  and  ship  accommodations,  the 
scientist  was  to  provide  a  selection  of  his  specimens 
for  the  company  museum." 

It  is  particularly  unfortunate  that  no  detailed 
account  of  Garrett's  activities  in  the  Fiji  Islands 
survives.  Because  of  unstable  political  conditions  of 
the  country  and  the  presence  of  savage  cannibals  he 
worked  under  extremely  difficult  conditions.  Un- 
doubtedly, he  was  befriended  by  a  few  American 
and  English  missionaries.  The  kingdom  had  for 
several  years  carried  a  heavy  financial  debt  to  the 
United  States  incurred  when  the  home  of  the 
American  consul  had  been  destroyed  by  a  mob.  Fiji 
had  even  sought  to  be  taken  over  as  a  protectorate 

^/t^i  /K 

■vy  -cr-. 

A^  .^nz:   fi-c^,  M  S.  S^:^x^^  ^  J^J.^^  ^^-^^ — ^ 

FIG.  2.  A  sample  of  Andrew  Garrett's  handirritiny  and  signature  fivni  an  ISX?  letter  irritten 
Hauhine  Island.  Society  Islands  t(i  W.  I).  Hartninn  of  West  Chester.  Pa  Oriyinai  in  the  Smithsonian 

Vol.  93(1) 

January  10, 1979 

THE  NAUTILUS      25 

first  by  Great  Britain  and  then  by  the  American 
government  but  both  offers  had  been  refused. 
Finally,  a  Confederacy  of  Independent  Kingdoms 
had  been  established  in  1865."  In  1868,  when 
Garrett  was  there,  a  Polynesian  Company  had  been 
formed  to  pay  U.  S.  claims  against  King  Cakobau  in 
exchange  for  concessions.  Looking  back  on  his  three 
year  experience  in  that  amazing  cluster  of  8(W  lit- 
tle-explored islands,  Garrett  wrote  in  a  letter  nine 
years  later  ". . .  in  the  Viti  (Fiji)  group  I  had  several 
narrow  escapes  both  from  the  natives  and  from 
drowning.  They  killed  several  whites,  including  a 
Missionary  while  I  was  there.  The  latter,  together 
with  several  native  teachers,  were  served  up  at  one 
of  their  cannibal  feasts.  Shortly  after  I  left  the 
group  there  were  a  number  of  white  residents 
killed  by  the  savages,  showing  what  risks  the  shell 
collector  experiences  when  searching  these 

However,  there  is  proof  of  Garrett's  success  in  his 
collecting  activities  in  the  Fiji  Islands.  The  sales 
catalogue  of  the  Museum  Godeffroy  notes:  "In 
regard  to  further  research  we  advise  that  Andrew 
Garrett,  well-known  through  his  collection  for 
Professor  Agassiz  and  the  fact  that  he  has  made  the 
South  Sea  Islands  his  main  task,  has  for  some  time 
extended  his  efforts  on  our  behalf.  The  first  ship- 
ment consisting  mostly  of  animals  of  the  Viti 
Islands  has  just  arrived  here.  It  consists  of  many 
interesting  species  such  as  amphibians,  fish, 
crustaceans  and  a  few  polyps,  worms  as  well  as  in- 

But  despite  there  somewhat  pleasing  results,  a 
real  tragedy  occurred  when  a  large  portion  of  his 
final  collections  were  destroyed  in  a  shipwreck. 
Writing  over  two  years  later  from  Tahiti  Garrett 
described  his  loss:  ".  . .  When  taking  my  departure 
after  two  years  hard  work  I  suffered  a  shipwreck 
and  lost  all  my  books  on  conchology,  all  my  dried 
plants,  Insects,  Bird  Skins,  part  of  my  Shells,  Notes 
and  Drawings  and  a  series  of  Portraits  of  Natives 
which  I  had  photographed.  Fortunately,  most  of  my 
shells  had  been  shipped  to  Samoa  in  another 
vessel."  He  concluded  by  saying  that  from  what  he 
had  saved  from  the  wreck  and  what  he  had  pre- 
viously shipped  to  Samoa,  I  find  about  1500 
species  of  Viti  (Fiji)  shells  and  probably  lost  one  or 
two  hundred  more.^' 

Last  Years  on  Huahine  (1870-1887) 

After  1870  Garret  spent  his  remaining  years  in 
the  Society  Islands.  He  had  established  a  home 
there,  having  made  several  stops  on  previous 
voyages.  One  should  not  be  surprised  that  he  chose 
the  attractive  island  of  Huahine,  ninety  miles  nor- 
thwest of  Tahiti,  as  his  permanent  home.  It  is  a 
volcanic  island  of  approximately  ten  square  miles 
in  area  with  twin  mountain  peaks,  one  of  them 
rising  over  2300  feet  above  the  sea.  His  own  descrip- 
tion, written  after  his  first  encounter  early  in  1858 
while  a  passenger  aboard  Captain  John  Leonard's 
whaleship.  Lydia,  says  "The  Island,  in  fact,  consists 
of  several  islets  which  are  separated  by  narrow 
channels.  They  present  a  bold  and  mountainous 
aspect,  and  are  clothed  in  the  most  luxurious  ver- 
dure from  the  water's  edge  to  the  summits.  .  .  A 
short  distance  back  there  arises  an  amphitheatre  of 
hills  and  mountains  which  are  covered  either  with 
tall,  rank  grass  or  dense  dark  forests,  and,  the 
whole  coast  consists  of  a  dense  mass  of  fruit  and 
splendid  flowering  trees,  all  combining  to  form  one 
of  the  most  delightful  tropical  scenes  I  ever  wit- 

Although  we  find  some  evidence  that  he 
travelled  (probably  by  small  sailing  canoe)  among 
the  nearby  islands  of  Raiatea  and  Moorea,  and  may 
have  made  occasional  business  trips  for  mail  and 
supplies  to  Papeete,  the  capital  and  chief  seaport, 
he  had  much  to  occupy  him  at  home.  He  was  busy 
making  up  selected  sets  of  his  duplicate  shells  and 
either  selling  or  exchanging  them  with  collectors  in 
Australia,  England,  France  and  the  United  States. 
This  work  which  involved  comparison  of  shell  iden- 
tifications led  to  extensive  correspondence  with 
both  amateur  and  professional  conchologists  in- 
cluding R.  E.  C.  Stearns  of  San  Francisco,  Berlin  H. 
Wright  of  Penn  Yan,  New  York,  Rev.  E.  R.  Beadle 
and  George  W.  Tryon  of  Philadelphia,  and  various 
others.  He  maintained  a  steady  correspondence 
with  Dr.  W.  D.  Hartmen  of  West  Chester,  Pen- 
nsylvania, and  some  of  these  letters  from  Garrett  to 
the  latter  individual  from  1874  to  1887  survive  in 
the  Carnegie  Museum,  Pittsburgh,  Pa.  In  the  mid- 
dle seventies  and  early  eighties  a  total  of  eighteen 
of  Garrett's  Scientific  papers  were  published  in  the 
Journal  of  the  Academy  of  Natural  Sciences  of 

26      THE  NAUTILUS 

January  10. 1979 

Vol.  93  (1) 

Philadelphia,  the  Journal  de   Conchyliolo(jie   in 
Paris,  and  other  scientific  periodicals. 

During  the  first  two  years  on  Huahine 
(1870-1872)  he  must  have  devoted  ojnsiderable 
time  and  energy  to  finishing  and  perfecting  the 
descriptions  of  the  collected  specimens  and  the 
watercolor  drawings  of  476  different  species  of 
fishes  from  Hawaii,  the  Society  Islands  and  the 
Fijis.  Johann  Caesar  Godeffroy  received  this 
material  in  1872  and  thought  so  highly  of  it  that  he 
had  the  project  edited  and  prepared  by  the 
celebrated  ichythyologist  of  the  British  Museum, 
Dr.  Albert  C.  L.  Gunther.  These  compri.sed  volumes 
1  and  2  of  the  prodigicjus  work,  "Andrew  Garrett's 
Fische  der  Sundsee",  published  in  Hamburg  as  part 
of  the  JounwJ  of  the  Museum  Godeffroy.  Un- 
fortunately, the  dissolution  of  the  business  of  J.  C. 
Godeffroy  and  Son  in  1879  delayed  further 
publication.  But  the  final  volume.  No.  3  was  issued 
in  1909.  This  work  remained  the  ultimate  authority 
on  the  fishes  of  the  Pacific  Ocean  for  almost  forty 

Little  has  come  to  light  of  Garrett's  private  life 
but  we  know  he  was  legally  married  to  a  woman 
named  Otari.  One  account  states  she  was  a 
Samoan^  and  another  informant,  Alvin  Seale, 
wrote  after  a  visit  to  Garrett's  home  at  Huahine  on 
January  1,  1903  that  Garrett's  wife  was  the 
daughter  of  a  high  chief  of  the  Island.  It  is  not 
knovm  whether  or  not  they  had  any  children, 
although  the  author  made  investigations  of  records 
on  this  topic  on  his  two  visits  to  Huahine  and 
Tahiti  in  1961  and  1974.  He  did  find  the  site  of 
Garrett's  dwelling  which  was  a  short  distance  from 
the  village  of  Fare.  Mr.  Seale  describes  it  as  "a  neat 
little  frame  house,  very  comfortable  and  situated  in 
a  nice  garden".  It  was  on  the  edge  of  a  bay  and  in 
sight  of  the  ocean.'' 

In  1878  Garrett  contemplated  going  to  New 
Caledonia  where  he  had  a  friend,  (probably 
Rossiter]  and  also  to  the  Solomon  Islands.  Instead 
he  wrote  Dr.  Hartman  of  reports  he  had  received  of 
massacres  of  the  whites  by  natives. ". . .  Not  having 
the  slightest  ambition  to  become  a  martyr  in  the 
name  of  Science,  I  think  it  will  be  the  wisest  course 
to  postpone  my  visit  to  those  savage  islands."'* 

Fortunately  this  remarkable  man  did  not  suffer 
the  kind  of  death  he  had  feared  in  the  far  off  can- 

nibal islands  but  in  a  sense  his  passing  was  no  less 
li-agic  as  he  died  of  a  lingering  case  of  cancer.  On 
June  25,  1887  he  wrote  his  friend  Hartman  in 
distant  Pennsylvania:  "As  regards  myself  I  have 
bad  news  to  write  and  think  this  probably  will  be 
my  last  letter  directed  to  you.  I  have  been  troubled 
some  time  back  with  a  diseased  mouth.  The  French 
doctors  in  Tahiti  call  it  a  ver>-  bad  cancer  and  it  has 
developed  too  far  to  be  successfully  treated  by 
•surgical  operation.  In  fact,  it  has  been  so  bad  and 
painful  that  life  is  a  burden  and  for  some  time  I 
have  been  unable  to  work  in  my  collection. . .  I  may 
jiossibly  linger  along  for  several  months.  I  am  too 
weak  to  write  much,  so  I  will  thank  you  over  and 
over  again  for  your  past  kindness  to  me. . ."" 

Garrett  died  on  November  1,  1887,  and  is  buried 
in  the  missionary  cemetery  under  a  large  tamanu 
tree  at  the  edge  of  the  village  of  Fare.  The  grave, 
with  an  inscribed  marker,  surrounded  by  a  .small, 
iron  fence,  still  survives  and  is  kept  in  good  repair 
at  the  expense  of  the  French  government. 

It  was  fortunate  that  the  English  minister.  Rev. 
Ebenezer  V.  Cooper,  Garrett's  neighbor,  wrote  a 
brief  but  fairly  accurate  obituary.  It  was  published 
with  a  bibliography  a  few  months  after  the  scien- 
tist's death  in  four  different  conchological 
magazines,  namely  "The  Conchologist's  Exchange", 
"The  West  American  Scientist",  "The  Journal  of 
Conchology"  (London)  and  "Science".' 

The  Personality  of  Andrew  Garrett 

What  few  descriptions  we  have  of  this  now 
almost  forgotten  explorer-naturalist  give  us  an 
impression  of  a  sincere  and  gifted  personality. 
Garrett  was  serious,  intelligent,  and  blessed  with 
prodigious  energy  and  drive.  Many  times  he  had 
been  in  great  danger  and  must  have  had  unusual 
physical  endurance,  having  been  exposed  at  sev- 
eral times  to  shipwreck,  tropical  diseases,  and  ex- 
treme fatigue.  One  of  the  most  striking  of  his 
characteristics  was  his  ability  to  overcome  the 
handicaps  of  very  limted  formal  education.  His 
missionary  friend,  the  Reverend  Ebenezer  Cooper 
wrote,  "He  was  self-taught  in  every  sense  of  the 
word  and  his  ability  and  achievements  were 
wonderful  and  striking."'  He  advanced  himself  in 
reading  and  he  so  practiced  himself  in  writing 
that  he  eventually  acquired  a  commendable  and 

Vol.  93  (1) 

January  10. 1979 

THE  NAUTILUS      27 

vigorous  prose  style.  His  artistic  ability,  very 
crude  at  first,  with  persistent  effort  enabled  him 
to  draw  not  only  with  scientific  precision  but 
with  aesthetic  quality  as  well.  As  for  languages, 
he  could  speak  Polynesian,  at  least  the  Hawaiian 
fonn  of  it,  and  probably  could  use  some  French 
because  of  its  commercial  and  social  usage  in  the 
Society  Islands  where  he  spent  one  third  of  his 

In  appearance,  he  was  a  lank,  partially  bald 
man  even  in  his  early  thirties,  and  had  deep 
cavernous  eyes  to  judge  from  the  only  portrait 
known  to  exist  which  he  sent  to  Agassiz  at  the 
time  he  was  engaged  as  a  collector  by  the  Mu- 
seum of  Comparative  Zoology  at  Harvard.  He  was 
slim,  apparently  of  medium  height  with  slightly 
stooped  shoulders,  side  whiskers  and  a  full  beard. 
He  looked  older  than  his  true  age  and  might  have 
passed  as  a  down-at-the-heels  missionary  or  even 
an  intellectual  beachcomer.  One  person  who  knew 
him  well  remarked,  "He  was  very  unpretentious 
and  no  one  from  casual  observation  would  im- 
agine him  to  be  a  savant.  .  .  Outside,  his  own 
special  study  of  Conchology,  he  was  deeply  read 
in  kindred  subjects  and  no  brand  of  natural 
history  seems  to  have  been  overlooked."  In  his 
later  life  he  possessed  a  good  working  library  of 
books  and  pamphlets  in  his  specialty  and  these 
books  are  now  preserved  in  the  Bishop  Museum 
in  Honolulu. 

Although  a  shy  man  and  apparently  not  en- 
dowed with  an  exuberant  personality,  he  instilled 
quiet  admiration  and  even  warmth  in  his  close 
friends.  Dr.  Wesley  Newcomb  was  so  pleased 
with  him  that  he  promised  to  name  a  new  species 
of  shell  in  his  honor.  One  of  his  closest  friends, 
William  Harper  Pease,  in  innumerable  letters  be- 
moaned his  long  absences  which  often  lasted  for 
years  at  a  time.  His  staunch  supporter,  the  mis- 
sionary Damon,  was  constantly  praising  him  and 
his  rare  qualities.  One  of  Garrett's  defects  seems 
to  have  been  his  poor  luck  in  business  affairs 
and,  perhaps,  his  over  confidence  in  individuals 
whom  he  trusted  who  took  advantage  of  him  in 
failing  to  pay  their  debts.  At  times,  he  seemed  to 
lack  normal  assertiveness. 

Encomiums  on  the  accuracy  of  his  scientific 
work  have  come  from  a  number  of  sources  in- 
cluding   Agassiz,    Pease,    Gunther,    and    more 

modern  scientists  such  as  Herbert  H.  Smith, 
Alvin  Seale,  Spencer  Tinker  and  others.  Especial- 
ly noteworthy  were  the  statements  of  the 
authority  on  Pmiuln  tree  snails  of  Polynesia  and 
Melanesia,  Dr.  Henry  E.  Crampton,  Professor  of 
Zoology  in  Columbia  University.  Crampton  made 
at  least  five  expeditions  over  a  period  of  18  years 
to  many  of  the  islands  where  Garrett  had  col- 
lected forty  or  fifty  years  earlier.  Crampton 
wrote,  "But,  above  all  others,  the  name  of  Garrett 
stands  out  prominently.  .  .  the  rich  fruits  of  his 
masterly  studies  are  the  shells  described  mainly 
by  Pease  and  the  precise  descriptions  of  their 
habitats  specified  with  an  exemplary  minuteness 
his  own  notable  monograph.  .  .  It  is  this  work  of 
Garrett's  that  forms  a  solid  basis  for  comparison 
of  the  present  intrinsic  and  distributional 
characteristics  of  Polynesian  species  in  their  con- 
ditions and  situations.  .  .""  The  same  appraisal 
has  been  given  by  Dr.  William  J.  Clench  who  said 
that  Garrett  deserves  great  credit  because  he 
recognized  the  hyperspecific  localities  and 
realized  the  value  of  numerous  species  from  a 
variety  of  regions.  He  perceived  the  changes  made 
in  a  species  by  changes  in  topography.'' 

One  man,  a  contemporary  from  another  profes- 
sion but  thoroughly  familiar  with  Garrett's  field 
work,  Rev.  Samuel  C.  Damon,  was  prophetic 
when  in  1863  he  wrote:  ".  .  .we  are  bold  to  assert 
that  there  are  but  a  few  men  in  the  world  whose 
labors  are  intrinsically  of  more  value  to  natural 
history.  Take  for  example,  his  late  exploration  of 
the  Society  Islands.  It  is  undoubtedly  more  im- 
portant than  that  of  any  English,  French  or 
American  exploring  expedition  which  ever  visited 
these  islands.  .  .  We  are  confident  no  explorer  is 
more  worthy  of  their  notice,  or  has  contributed 
more  largely  to  widen  the  sphere  of  science  and 


The  author  is  especially  indebted  to  his  late 
cousins,  Francelia  and  Aurilla  Leonard  of 
Fairhaven,  Massachusetts,  who  gave  him  a  set  of 
over  250  watercolors  and  drawings  of  fishes  and 
shells  made  by  Andrew  Garrett.  Many  scientists 
and  museum  workers  assisted  in  his  forty-six- 
year  researches,  especially  William  J.  Clench  of 

28      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

Harvard  University;  the  late  E.  W.  Gudger  of 
the  American  Museum  of  Natural  History;  the 
late  Henry  E.  Crampt^m  of  Barnard  College; 
Peter  Buck,  Margaret  Titoomb,  Yoshio  Kondo, 
Eklward  Br>'an  and  Donald  M.  Mitchell,  all  of  the 
B.  P.  Bishop  Museum;  Ruth  E.  Lee  and  Ann 
Blum,  Museum  of  (x)mparative  Zoology,  Harvard; 
Spencer  M.  Tinker  of  the  Waikiki  Aquarium; 
Albert  Panning  of  the  Hamburg  Zoologischen 
Staatsinstituts;  Barbara  Johnson  of  Princeton, 
New  Jersey;  Yosihiko  Sinoto  of  Huahine  and 
Aurora  Natua  of  the  Papeete  Museum;  and,  for 
assistance  for  1961  travel  expenses,  the  Explorers 
Club  of  New  York  and  the  Frank  M.  Chapman 
Memorial  Fund  of  the  American  Museum  of  Nat- 
ural History.  Dean  Amadon,  R.  Tucker  Abbott 
and  many  others  gave  of  their  time  and 
assistance,  for  which  I  am  very  grateful. 


Andrew   Garrett's   Fische   der  Sudsee   in    Journal   des 
Museum  Godeffroy,  Hamburg  1873/7.5  Vol.  1  and  2,  Vol. 
3, 1909.  written  and  edited  by  Albert  C.  L.  G.  Gunther. 
Florence  M.  .Spoehr.   White  Falcon.  Pacific  Books.  Palo 
Alto.  Calif.  196.3.  pp.  101-119. 

Ebenezer  V.  Cooper.  "Obituary  of  Mr.  Andrew  Garrett" 
in  Journal  of  Conchology  (Leeds)  1888,  Vol.  V:  317-318. 
Also  West  American  Scientist,  vol.  4,  p.  19. 
Letter  from  A.  G.  to  James  M.  Barnard,  dated  Hilo, 
Hawaii,  April  29,  1857.  Original  in  M.  C.  Z..  Harvard 

Crew    List    of    the    Bark,    Edward.     Old     Dartmouth 
Historical  Society,  New  Bedford.  Mass. 
77ie  Friend.  Honolulu,  (newsiiaper)  October  13,  18.58  p.  76 
article.  "Mr.  Andrew  Garrett,  the  Naturalist"  by  Samuel 
C.  Damon. 

Baker,  Ray  Jerome,  "Honolulu  in  18,53",  Honolulu,  19.50. 
Letter  from  Dr.  Wesley  Newcomh  to  Garrett,  Honolulu 
Nov.  27, 18.54.  Original  in  Bishop  Museum  Library. 
Kay,   A.    E.   "Biography   of  William    Harper   Pease   in 
Nemouria,  Occasional  Papers  of  the  Delaware  Museum  of 
Natural  History,  no.  16.  Dec.  .30. 197.5. 
Garrett.  Andrew  letter  to  I/iuis  .^gassiz.  Hilo,  Hawaii 
.Jan.  29. 18.5.5.  Original  in  M.  C.  Z.  Harvard  University. 
Andrew    Garrett    to    James    M.    Barnard,   dated    Hilo, 
Hawaii  Oct.  10, 18.5().  Original  in  M.  C.  Z. 
The  Friend,  Honolulu  (newspaper),  July  1,5, 18.59  p.  .52. 
Letter  from  .John  W.  Ix>onard  to  his  wife,  on  board  ship 
Lydia,  March  2,  18.57.  Original  in  po.ssession  of  Mrs.  Bar- 
bara Johnson,  Princeton.  N.  J. 

Letter  from  Louis  Agassiz  to  J.  M.  Barnard  (intended  for 
Garrett),  from  Cambridge.  Mas.s.  .■^ug.  28,  1S.57.  Original 

Letter  A.  G.  to  J.  M.  Biirnanl.  I'apai  Puna,  Island  of 






16.  One  of  two  undated  letters  from  Agassiz,  preserved  in 
the  Andrew  Garrett  manuscripts  in  the  Library  of  the 
Bishop  Museum.  Honolulu,  Hawaii. 

17.  Greene,  K.  W.  Articles  in  Hawaiian  Shell  News.  Issues 
of  April  through  October.  1960.  Honolulu.  Hawaii. 

18.  Mrs.  James  Warren.  "The  Morning  Star":  History  of  the 
Chi Idrens  "Missionary  Vessel".  Boston,  1860. 

19.  Letter  from  A.  Garrett  to  J.  M.  Barnard  containing  his 
Kingsmill  Island  Journal,  dated  Honolulu.  Feb.  8,  1860. 
Original  in  M.  C.  Z.  Library.  Harvard  University. 

20.  Board  of  Trustees,  Museum  of  Comparative  2yOology, 
Harvard  University.  Cambridge,  Mass.  -fnl  Annual 
Report.  1862. 

21.  Andrew  Garrett  "The  Terrestrial  Mollusca  Inhabiting 
the  Society  Islands"  Proceedings  of  the  Academy  of 
Natural  Sciences  of  Philadelphia.  Journal  9,  1884-1888,  p. 

22.  Samuel  C.  Damon  article  in  The  Friend,  Honolulu.  Aug. 
4, 1863.  New  Series  Vol.  2,  p.  8. 

23.  Andrew  Garrett,  letter  to  J.  M.  Barnard  from  Hilo, 
Hawaii,  April  29, 1857. 

24.  W.  H.  Pease,  letter  to  A.  Garrett,  Honolulu.  Sept  2,  1862. 
Original  in  Bishop  Museum  Library. 

25.  Letter  from  W.  H.  Pease  to  A.  Garrett,  Jan.  20,  1864. 
Original  in  Bishop  Museum  Library. 

26.  A.  Panning.  "Beitrage  zur  Geschichte  des  Zoologischen 
Staatsinstituts  und  Zoologischen  Museums  in  Hamburg." 
Hamburg  Dec.  1956. 

27.  Letter  from  J.  C.  Godeffroy  to  Theodor  Weber,  dated 
Hamburg  Jan.  25,  1867,  copy  provided  to  WST  by  his 
descendant  Caesar  Godeffroy. 

28.  Judy  Tudor,  Editor  and  Compiler  Handbook'  of  Fiji. 
Fourth  Edition.  Pacific  Publications.  Sydney.  N.  S.  W. 
1972  p.  51,  .53.  .57. 

29.  Letter  A.  Garrett  to  Dr.  W.  D.  Hartman,  West  Chester, 
Pa.,  dated  Huahine,  Society  Islands.  Nov.  28,  1878. 
Original  in  Carnegie  Museum.  Pittsburgh.  See  also  The 
Bejit  of  the  Nautilus  (R.  T.  Abbott  ed..  1976).  p.  260.  for  a 
similar  letter  written  by  W.  D.  Hartman  to  H.  A.  Pilsbry 
about  1896! 

.30.    Information  supplied  by  A.  Panning  of  Hamburg  19.55  to 

W.  S.  Tliomas. 
.31.    lietter  fnim   A.  Garrett  to  J.  G.  Anthony.  Cambridge, 

Ma&s.  Sept.   15.   1872  from   Huahine.   Original   in   MCZ 

Library,  Harvard  University. 
32.    Introduction   by   Dr.  A.  C.   L.   Gunther  to  Fi.sche  der 

Sudsee.  Hamburg,  1873. 
.33.    Memo  from  Alvin  Seale  M.D.  in  copy  of  his  book  "The 

Golden    Cloak"    in    Library   of  the    Bernice   P.    Bishop 

Museum,  Honolulu. 
31.    l^elter  from  A.  Garrett  to  W.  D.  HartniJin  Feb.  10.  1879 

in  Carnegie  Museum,  Pittsbui'gh,  Pa. 

35.  I/etter  from  A.  Garrett  to  W.  D.  Hartman.  dated 
Huahine  .June  2.5, 1887. 

36.  Cranipton,  Henry  E.  "Studies  on  the  Variation. 
Distribution  and  of  the  Genus  Partula".  Carnegie  In- 
stitution, Washington.  D.C,  1916, 

37.  Clench,  William  J.  Conversation  with  W.  S,  Thomas, 
Cambridge,  Mass.  Nov.  2, 1931. 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      29 


Douglas  S.  Jones 

Department  of  Geological  and  Geophysical  Sciences 
Princeton  University 
Princeton,  N.J.  08540 


JTie  cornmetisal  relationship  between  the  marine  bivalve,  Arctica  islandica,  and 
the  nemertean  Malacobdella  grossa  along  the  Atlantic  coast  of  North  America  has 
not  heretofore  been  reported,  although  it  has  been  documented  in  European 
specimens.  A  single  M.  grossa  was  found  living  in  a  small  Ocean  Quahog  dredged 
from  offshore  New  Jersey.  In  addition,  the  nemertean  occurred  in  the  venerid 
clam.  Pitar  morrhuana,/rom  the  same  locality  with  a  frequency  of  28%.  Examina- 
tion of  numerous  specimens  of  A.  islandica /or  M.  grossa  with  negative  results  sug- 
gests this  occurrence  is  atypical. 

The  commensal  nemertean,  Malacobdella  grossa 
(Miiller),  ranges  widely  along  the  North 
American  Atlantic  coast  where  several  species  of 
bivalves  are  known  to  serve  as  hosts.  Coe  (1943) 
cites  Mercenaria  mercenana.  Mya  arenatia.  and 
Cras,^ost7ra  virginica  as  known  hosts  of  this  com- 
mensal. Porter  (1962)  added  Mercenaria 
campechiensis  to  this  list,  and  Ropes  discovered 
M.  gro.fsa  in  the  Morrhua  Venus,  Pitar  mor- 
rhuana.  The  aforementioned  species  are  among 
seventeen  bivalves  known  to  serve  as  hosts  for 
the  genus  Malacobdella  and  fourteen  for  M. 
grossa  (Ropes,  1967). 

While  Coe  (1943)  lists  Arctica  islandica  as  a 
host  of  Malacobdella  grossa  in  European  waters. 
Ropes  (1967)  points  out  that  in  the  western  At- 
lantic M.  givssa  is  not  known  from  either  Arctica 
islandica  or  Spisula  solidissima,  two  widely  dis- 
tributed and  abundant  Middle  Atlantic  coast  bi- 
valves (Merrill  and  Ropes,  1969).  This  is  unusual, 
since  Malacobdella  occurs  in  two  other  species  of 
Spisula  (S.  sachalinensis  from  Japan  and  S 
stultorum  from  Europe).  Brunberg  (1964),  in  re- 
porting on  nemerteans  from  Danish  waters,  says 
Malacobdella  grossa  was  commonly  collected  in 
the  mantle  cavity  of  Cyprina  (now  Arctica)  is- 
landica in  the  areas  investigated,  i.e.,  the 
Gullmarfjord,  the  neighborhood  of  Frederikshavn 
and  Laes^,  in  the  northern  J0resund.  Nevertheless, 

Ropes  (1967)  reports  examining  thousands  of  surf 
clams  and  numerous  ocean  quahogs  from  the  At- 
lantic coast  with  negative  results. 


Specimens  of  Arctica  islandica  were  obtained 
on  27  June  1977  by  a  commercial  clamming  vessel 
fishing  with  a  "hydraulic  clam  dredge  at  a  loca- 
tion ('^73°40'W  and  40°15'N)  approximately  32 
kilometers  offshore  from  Asbury  Park,  New 
Jersey,  in  water  30  meters  in  depth.  Several 
specimens  of  Pitar  motrhuana  were  caught  with 

FIG.  1.  Arrows  shmv  the  nemertean.  Malacobdella  grossa  at- 
tached to  the  mantle  of  the  Ocean  Quahog.  Arctica  islandica 
after  removing  the  left,  valve  and  visceral  mass.  Scale  at  right 
has  centimeter  divisions. 


January  10, 1979 

Vol.  93  (1) 

the  ocean  quahogs  in  the  same  dredge  hauls. 
Twenty  ocean  quahogs  of  various  sizes  and  18 
specimens  of  P.  morrhuana  were  randomly 
selected  from  the  dredge  hauls,  opened  in  the 
laboraton,'.  and  examined.  Shell  lengths  were 
measured  and  the  soft  body  tissues  searched  for 
other  organisms.  When  the  single  nemertean, 
MnlacdhdeUa  groni^a,  was  discovered  in  an  in- 
dividual Arctica  i'slandica,  it  was  identified, 
measured,  photographed,  and  preserved. 


A  single  specimen  of  Airtira  Mandicn  con- 
tained the  commensal  nemertean  Malacobdella 
grossa  living  in  its  mantle  cavity  (Fig.  1).  The 
clam,  a  smaller  individual  than  those  normally 
caught,  had  a  shell-length  of  55  mm.  The  nemer- 
tean was  easily  recognized  by  the  presence  of  a 
ventral,  rear  sucker  found  attached  to  the  mantle 
of  the  clam,  hi  a  relaxed  live  state  it  measured  21 
mm  in  length.  Of  the  eighteen  specimens  of  Pilar 
morrhuana  collected  from  the  same  dredge  haul, 
five  contained  individuals  of  M.  grossa  for  an  in- 
cidence of  infection  of  28%.  Shell-lengths  of  the 
Pitar  specimens  ranged  from  39  mm  to  58  mm 
and  averaged  44  mm  while  M.  grossa  occurred  in 
individuals  ranging  from  41  mm  to  58  mm.  The 
worms  ranged  between  20  and  28  mm  in  length 
and  each  host  contained  only  a  single  nemertean. 


The  single  occurrence  of  Malacobdella  grossa  in 
an  individual  of  Arctica  islandica  is  apparently 
very  rare  for  the  Atlantic  coast  of  the  United 
States  and  Canada.  Though  Brunberg  (1964) 
found  ocean  quahogs  commonly  hosting  M  gmssa 
in  Danish  waters,  no  incident  of  this  relationship 
has  ever  been  reported  on  this  side  of  the  Atlan- 
tic. Ropes  (1967,  personal  communication)  has  ex- 
amined numerous  specimens  of  Arctica  without 
finding  any  evidence  of  infection  by  M.  grossa.  In 
addition,  I  have  opened  almost  one  thousand 
specimens  of  Arctica  islandica  and  Spisula 
solidissima  for  various  research  purposes  without 
encountering  another  nemertean. 

The  single  infected  clam  was  smaller  than 
those  usually  caught  by  commercial  clamming  ap- 
paratus and  hence  smaller  than  those  usually  ex- 
amined. It  was  similar  in  size  to  the  infected  in- 
dividuals of  Pitar  morrhuana  collected  in  the 
same  dredge  haul.  Nevertheless,  numerous  com- 
parably-sized Arctica  have  been  examined  with 
negative  results.  Examination  of  hundreds  of 
specimens  of  both  surf  clams  and  ocean  quahogs 
for  M.  grossa  has,  except  for  this  one  incident, 
yielded  negative  results.  The  evidence  supports 
Ropes'  (1967)  conclusion  that  Malacobdella  grossa 
does  not  normally  associate  with  either  Spisula 
solidissima  or  Arctica  islandica  along  the  Atlan- 
tic coast  of  North  America. 


I  would  like  to  thank  Mr.  John  Ropes  of  the 
National  Marine  Fisheries  Service  for  critically 
reading  the  manuscript  and  Dr.  Donald  Baird  of 
the  Princeton  Natural  History  Museum  for 
photographing  the  specimen.  The  cooperation  of 
Snow  Foods.  Inc.  of  Pt.  Pleasant.  N.  J.  is  greatly 
apprec-iated.  This  report  is  an  outgrowth  of  other 
work  on  neritic  bivalves  supported  by  NOAA  Sea 
Grant  #04-6-158-44076  to  Dr.  Ida  Thompson  of 
Princeton  University. 


Brunberg.  L.  19&4.  On  the  nemertean  fauna  of  Danish  waters. 
Ophelia  1:77-111. 

Coe.  W.  R.  1943.  Biology  of  the  nemerteans  of  the  Atlantic 
coast  of  North  America.  Trans.  Cotmecticut  Acad.  Arts  Sci. 

Merrill.  A.  S.  and  .J.  W.  Ropes.  1969.  The  general  distribution 
of  the  surf  clam  and  ocean  quahog.  Pivc.  Natl  Shellfish. 
Assoc.  59:40-45. 

Porter.  H.  .1.  1962.  Incidence  of  Malacobdella  in  Mercenaria 
campechiensis  off  Beaufort  Inlet.  North  Carolina.  Pmc. 
Nat  I  Shellfish.  Assoc.  53: 133-145. 

Ropes,  J.  W.  1%7.  Malacobdella  grossa  in  Pitar  morrhuana 
and  Mercenaria  campechiensis.  The  Nautilus  81:37-40. 

.      1966.     Pitar      morrhuana,      new     host      for 

Malarobdetla  grossa.  The  Nautilus  79:128-130. 

Vol.  93(1) 

January  10, 1979 

THE  NAUTILUS      31 



Gary  L.  Pace,  Ernest  J.  Szuch  and  Richard  W.  Dapson 

Biolog>'  Department,  University  of  Michigan-Flint 
Flint,  Michigan  48503 


SCUBA  was  used  in  August,  197^.  to  determine  the  depth-distribution  of  mails 
at  two  localities  in  New  Mission  Bay,  a  small  inlet  of  Grand  Traverse  Bay.  Lake 
Michigan.  Five  0.5m^  samples  were  collected  at  20  ft  intervah  along  each  of  6 
depth  contours  at  both  localities  (5.  10,  15.  20,  25.  30  ft  and  10,  12.5,  15,  20,  25,  30 
ft).  At  the  2  localities  Gyraulus  parvus  (Say)  attained  peak  densities  of  2.U/m}  and 
28.Jt/m^  on  small  pebbles  at  10  ft  depths.  These  densities  represent  60%  and  92%  of 
the  Gyraulus  collected  at  the  two  localities.  Most  Marstonia  decepta  (Baker)  fAm- 
nicola  lustrica  of  Pilsbry)  and  Valvata  tricarinata  (Say)  were  collected  from  sand- 
silt  .wbstrates.  Both  M.  decepta  and  V.  tricarinata  reached  their  maximum  den- 
sities at  the  10  ft  depth  at  one  locality  (16i.8/m^  and  29.6/m^,  respectively),  and  at 
the  12.5  ft  depth  at  the  other  (152.i/m^  and  h9.2/m^,  respectively).  These  densities 
represent  60%  and  5k%>  of  the  M.  decepta  and  37%  and  30%  of  the  V.  tricarinata 
specimens  collected  fiv7n  the  two  localities. 

Most  studies  of  Great  Lakes'  macrobenthos 
have  understandably  been  large  scale  dredging 
operations  dealing  primarily  with  profundal 
organisims  (Eggleton,  1936,  1937;  Mema,  1%0; 
Powers  and  Robertson,  1965;  Robertson  and  Alley, 

FIG.  1.    Location  ofNew Mission  Bay (mmicin  inset). 

1966;  Henson,  1966)  or  with  specimens  collected 
from  the  upper  littoral  zone  and  beach  drift 
(Goodrich,  1932;  Heard,  1962a,  1962b;  Henson  and 
Herrington,  1965).  Beach  drift  specimens,  of  course, 
tell  us  very  little  of  the  preferred  habitat,  and  a 
number  of  papers  have  demonstrated  problems 
with  the  reliability  and  efficiency  of  several  types 
of  bottom  samplers  (Beeton,  Carr,  and  Hiltunen, 
1965;  Milbrink  and  Wiederholm,  1973).  ahers 
have  shown,  however,  that,  visibility  permitting, 
SCUBA-assisted  studies  can  provide  direct,  quan- 
titative collections  from  a  wide  variety  of 
substrates  (Cvancara,  1972;  Harmon,  1972;  Clam- 
pitt,  1973,  1974).  This  paper  reports  on  a  SCUBA 
study  of  the  depth  distribution  of  3  littoral 
gastropod  species  at  2  discrete  localities  in  New 
Mission  Bay,  a  small  inlet  on  the  western  side  of 
Grand  Traverse  Bay,  Lake  Michigan  (Fig.  1). 

New  Mission  Bay  narrows  irregularly  from  a 
maximum  width  at  its  mouth  of  about  2.3  km, 
due  North  for  a  distance  of  approximately  1.7  km 
(Fig.  2).  A  paved  road  circumscribes  the  bay 
within  a  few  hundred  meters  at  all  points.  Be- 
tween the  road  and  the  bay,  mixed  coniferous- 
deciduous  woods  dominate  along  the  east  shore 
and  alternate  with  cleared  land  on  the  west  and 

32      THE  NAUTILUS 

January  10, 1979 

Vol.  93  (1) 

FIG.  2.  Cantimr  map  of  New  Mission  Bay  showing  positions 
of  Oniena  Beach  and  Oniena-T)ni'erse  Yacht  Club  collecting 
localities  (adapted  from  U.S.  Army  Corps  of  Etiyiiieers  Chart 
LS.  706).  Scale  =  ■5(X)ft/unit:  Contour  Interval  =  6fi. 

north  shores.  The  very  small  town  of  Omena  with 
its  marina  and  public  beach  rests  at  the  bay's 
Northwest  comer  while  a  few  cottages,  perma- 
nent residences  and  a  yacht  club  are  scattered 
among  the  trees  along  the  east  shore.  The  bot- 
tom-slopes are  ver>'  gradual  on  both  sides  at  the 
outer  end  of  the  bay.  On  the  western  side  of  the 
inner  half  of  the  bay,  however,  the  bottom-slope 
is  at  first  very  gradual  and  then  drops  off 
abruptly.  While  there  are  local  differences 
discussed  below,  the  northern  and  northeastern 
bottom-slopes  deepen  rather  regularly.  Within 
New  Mission  Bay,  only  one  region  in  the  north- 
west corner  is  known  to  exceed  60  ft  in  depth 
(Fig.  2).  Temperature  measurements  of  21°  C 
down  to  30  ft  and  20°  C  at  40  ft  were  recorded  in 
the  northeastern  part  of  the  bay  on  August  17, 
1974.  These  correspond  well  with  Lauffs  (1957) 
data  for  this  region  of  (Jrand  Traverse  Bay. 
Lauffs  report  also  provides  a  Secchi  disk  trans- 
parency measurement  of  9-10  m  and  notes  that  sur- 

face currents  pass  the  mouth  of  New  Mission  Bay 
in  a  WSW  direction  at  this  time  of  year. 


SCUBA  was  used  to  study  the  depth  distribu- 
tion of  snails  along  two  "transects"  in  New  Mis- 
sion Bay  (Fig.  2).  One,  designated  "Omena  Beach" 
(O.B.),  runs  south  from  a  point  about  100  yds  east 
of  the  public  beach  at  the  northern  end  of  the 
Bay.  Here  the  bottom-slope  increases  gradually  in 
depth  to  about  15  ft  and  then  drops  off  rapidly  to 
depths  greater  than  60  ft.  The  predominantly 
sandy  bottom  gradually  becomes  overlain  by  a 
thin  layer  of  colloidal  organic  sediment  as  the 
depth  increases.  The  second  transect,  "Omena- 
Traverse  Yacht  Club"  (Y.C.),  extends  west  from 
the  east  shore  about  ,50  yds.  south  of  the  yacht 
club.  The  bottom  here  is  strewn  with  large  boul- 
ders at  the  edge  and  increases  rapidly  in  depth  to 
about  10  ft  where  the  substrate  becomes  sandy 
and  the  slope  levels  off  for  100-150  ft.  Here  the 
organic  content  of  the  substrate  increases  as  the 
depth  increases  rapidly  to  more  than  45  feet. 
Macrophjtes  were  essentially  nonexistant  at  both 
study  areas. 

Each  transect  consisted  of  six  100  foot  lines 
marked  at  20  ft  intervals  and  placed  approx- 
imately parallel  to  shore  along  depth  contours. 
These  were  established  at  depths  every  5  feet  out 
to  30  feet  at  Omena  Beach,  and  10  ft",  12.5  ft,  15 
ft,  20  ft,  25  ft,  and  30  ft  off  the  Yacht  Club. 
Depths  were  determined  using  a  calibrated  line 
tied  to  a  float  and  were  checked  using  diver's 
depth  gauges.  A  sand-filled  "Hula-Hoop"  was  se- 
quentially placed  at  the  center  of  each  20  ft  sec- 
tion establishing  a  constant  sample  area  (0.4KmM. 
Hand-picked  snails  were  placed  into  prelabeled 
"zip-lock"  type  plastic  bags.  Thirty  snail  samples 
were  thus  collected  directly  from  each  of  the  two 
study  areas. 


The  following  mqllusks,  in  order  of  decreasing 
maximum  density  (X/m'),  were  collected  from  the 
two  localities:  Marstonia  deceptn  (Baker)  (.4m- 
nicola  lustrica  of  Pilsbry)  (164.8),  Valrata 
tricarinata  (Say)  (49.2),  Gifraulus  parvus  (Say) 
(28.4),  Physa  .sp.  (3.6),  Pisidium  sp.  (2.4),  Cinciri- 

Vol.  93(1) 

January  10, 1979 


TABLE  1.  Depth  Distribution  <\f  Snails  near  Omena  Beach.  Data  are  mean  den^ties  (^/m')  nf  5  samples  (n  =.V  at  each  depth, 
with  Standanl  Enrrr  (SE)  in  parentheses:  %  of  the  species-populatian  at  each  depth:  %  nf  the  snail  community  at  each  depth 
represented  by  each  species. 









G.  parvus  (Say) 



2.U   (  1.3) 








0.8  (  0.7) 
0.8  (  O.k) 










H.  decepta  (Baker) 


7.6  (  1.3) 



(=  A.  lustrica  Pllsbry) 


164.8  (Ik.k) 



15.0  (  5.2) 




18.0  (  2.0) 




38.0  (14.;+) 




2.8  (  1.3) 


67. 5 

V.  trlceirinata  (Say) 


11.2  (  1.7) 
29.6  (  3.7) 




20.8  (  7.6) 




3.6  (  1.6) 
13-6  (  7.3) 







0.4  (  0.4) 



natia  cincinnatiensis  (Anthony)  (2.0),  Goniobasis 
livescens  (Menke)  (1.2),  Lymnaea  decampi 
(Streng)  (0.8),  LampsUis  mdiata  .vliquoidea 
(Barnes)  (0.2),  Anodonta  graudis  (Say)  (0.1).  Due 
to  the  substantial  differences  in  relative  abun- 
dance, only  the  data  for  the  first  three  species  are 
presented  (Tables  1, 2,  Figures  3-6)  in  any  detail. 

Gip-aulus  parvus,  rarest  of  the  three  most 
prominent  species,  was  most  commonly  found  on 
the    sand-gravel    substrates    at    10    ft    in    both 

localities.  Densities  of  2.4/m^  and  28.4/m^  repre- 
sent 60%  and  92.2%  of  the  specimens  collected  at 
O.B.  and  Y.C.,  respectively  (Tables  1,  2).  Thus,  at 
10  ft,  Gijraulus  represented  only  about  1%  of  the 
3-species  community  at  O.B.,  but  as  much  as  30% 
of  that  community  at  Y.C.  The  distribution  of 
Marstonia  decepta  at  Omena  Beach  (Table  1,  Fig. 
3)  appears  bimodal,  with  a  major  peak  at  10  ft  of 
164.8/m^  and  a  minor  one  of  38/m^  at  25  ft.  At 
the  Yacht  Club  locality  (Table  2,  Fig.  4),  however, 

TABLE  2.  Depth  Distribution  of  Snails  near  Omena-Traverse  Yacht  Club.  Data  are  mean  densities  (X/m^)  of  5  samples  (n=.5) 
at  each  depth,  with  Standairl  Error  (SEj  in  parentheses:  %  of  the  species-population  at  each  depth:  %  of  the  snail  cornmunity  at 
each  depth  represented  by  each  speciex. 

%  % 










G.  parvus  (Say) 
















H.  decepta  (Baker) 




(=A.  lustrica  Pilsbry) 
















V.  tricarinata  (Say) 



































75. '^ 






















January  10, 1979 

Vol.  93  (1) 



/  m 




M.  dec  ept  a 


01  I  I  I  I 

5  10  15         20         25         30 



FIG.  3.  Depth  distributimt  of  Marstonia  decepta  at  Omena 
Beach.  Horiznnal  Line  =  X/m':  Vertical  Bar  =  ±  1  Standard 
Error;  Vertical  Line  =  Range  of  density  among  5  samples  at 
each  depth. 

Marstonia  shows  a  definitely  unimodal  distribu- 
tion with  a  maximum  density  of  152.4/m^  at  12.5 
ft.  These  ma.ximum  densities  represent  nearly 
60%  of  the  Omena  Beach  specimens  and  almost 
54%  of  the  Yacht  Club  specimens  taken  from  the 
6  depths  at  each  locality.  Marstonia  was  obvious- 
ly the  dominant  member  of  the  molluscan  com- 
munities of  the  5  deeper  stations  (68-87%)  at  O.B. 
(Table  1)  and  of  the  3  shallower  stations  (61-75%) 
at  Yacht  Club  (Table  2). 

Valvata  tricarinata  appears  to  demonstrate 
bimodal  distributions  at  both  localities,  but  with 
distinct  maxima  in  each  case.  At  Omena  Beach 
(Table  1,  Fig.  5),  Valvata  reached  its  peak  density 
of  29.6/m^  at  10  ft.  After  decreasing  rapidly  from 
20.8/m^  at  15  ft  to  3.6/m^  at  20  ft,  Valvata  in- 
creased again  to  13.6/m'  at  25  ft.  A  similar,  but 
less  dramatic  bimodal  distribution  was  found  at 
the  Yacht  Club  site  (Table  2,  Fig.  6).  Here,  the 
maximum  density  (49.2/m')  occured  at  12.5  ft. 
This  declined  to  29.6/m'  at  15  ft  and  increased 

again  to  38.0/m^  at  20  ft.  The  maximum  densities 
represent  only  about  37%  of  the  specimens  col- 
lected at  Omena  Beach  and  less  than  31%  of  the 
specimens  taken  at  the  Yacht  Club  site.  V.alvata 
was  the  dominant  member  of  the  communities  of 
the  5  ft  station  at  Omena  Beach  (Table  1)  and  of 
the  3  deeper  stations  off  the  Yacht  Club  site. 
(Table  2). 


The  paucity  of  similar  studies  prevents  the 
direct  comparison  of  these  data  with  those  of 
others  and  the  causes  for  the  demonstrated 
stratification  can  only  be  surmised.  Since  all  sta- 
tions were  within  the  elipimnion,  the  chemistry 
of  these  environments  would  be  expected  to  be 
rather  homogeneous.  Physico-chemical  differences 
in  the  benthic  microhabitats,  if  they  e.xist,  may 
therefore  be  assumed  to  be  the  direct  result  of 
substrate-biota  interactions.  Harman  (1972), 
reporting  on  mollusks  from  three  central  New 
York  lakes,  suggested  that  definite  relationships 





M.  dec  epia 








+  4-1 


15         20         25 


FIG.  4.    Depth  distribution  of  Marstonia  decepta  at  Omena- 
Traverse  Yacht  Cluh. 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      35 

exist  between  mollusk  distribution  and  substrate 
patterns.  The  substrates  of  ail  our  stations  fall 
into  one  of  his  five  broad  types:  "Littoral  silt  and 
detritus -fine  organic  and  inorganic  materials." 
According  to  Harman,  this  is  the  preferred  sub- 
strate of  only  one  of  our  three  species,  namely 
Valvata  tricarinata.  The  other  two  species, 
Gip-aulus  panms  and  Mastnnia  decepta  are  said 
to  prefer  "Autochthonous  organic  matter  -  aquatic 
plants  and  their  decaying  remains." 

Of  121  collections  of  Gip-avbis  [mrvus  by  Har- 
man (1972),  94  were  from  substrates  of  auto- 
chthonous organic  matter,  while  only  9  were  from 
littoral  silt  and  detritus.  Considering  that  there 
were  no  aquatic  macroph>1:es  near  any  of  the  sta- 
tions we  studied,  it  is  perhaps  surprising  the 
Gyranlus  were  found  to  represent  as  much  as 
30%  of  the  molluscan  community  at  the  10  ft 
depth  of  the  Yacht  Club  locality.  This  was, 
however,  the  only  station  in  which  Gip'aulus  was 
at  all  common.  As  indicated  above,  Gyrmdus  was 
frequently  collected  from  small  pebbles  rather 
than  from  the  more  abundant  sand  and  flocculent 
organic  sediments.  This  may  reflect  the  require- 
ment of  a  more  stable  substrate  usually  available 
in  the  form  of  higher  aquatic  plants  in  these 
snails'  preferred  habitats. 

Three  observations  suggest  that  major  com- 
ponents of  the  niches  of  Marstonia  decepta  and 
Valvata  tricarinata  overlap:  (1)  the  occurrence  of 


4  0 




V.   tricarinata 




5  10  15         20        25         30 


FIG.  5.    Depth  distribution  of  Valvata  tricarinata  at  Omena 



X/  2     ''O 


V.  tricarinata 





5  to  15         20         25         30 


FIG.  6.  Depth  distribution  of  Valvata  tricarinata  at 
(hnertn-Tnwerse  Yacht  Club. 

both  species  at  all  our  collecting  stations;  (2)  the 
co-occurrence  of  the  peak  densities  of  these  two 
species  at  10  ft  (O.B.)  and  12.5  ft  (Y.C.)  indicating 
the  preferred  conditions  for  both  species;  (3)  the 
co-occurrence  of  secondary  density  peaks  at  the 
25  ft  depth  at  O.B.  That  Marstonia  is  better 
adapted  to  the  conditions  in  New  Mission  Bay  is 
indicated  by  the  fact  that  it  was  the  dominant 
species  in  8  of  the  12  communities  studied.  Since 
a  higher  percentage  of  the  Marstonia  specimens 
were  collected  at  the  10  ft  (60%)  and  12.5  ft  (54%) 
depths,  we  might  infer  that  this  species  has  a 
stronger  preference  for  (i.e.,  is  better  adapted  to 
the)  conditions  at  these  depths  than  is  Valvata 
(37%  &  31%).  At  neither  location  did  Valvata 
(15%  &  24%)  dominate  the  communities  of  these 
depths.  At  Omena  Beach,  Valvata  dominated  only 
the  5  ft  depth,  while  Marstonia  dominated  all  5 
greater  depths.  Off  the  Yacht  Club  however,  Mar- 
stonia donated  all  three  shallower  depths,  while 
Valvata  was  obviously  the  dominant  member  of 
the  three  deeper  communities.  Thus  it  seems  that 
Marstonia  is  not  only  generally  better  adapted  to 
the  New  Mission  Bay  conditions,  but  specifically 
best  adapted  to  those  at  the  10-12.5  ft  depths. 
Valvata,  on  the  other  hand,  seems  less  spe- 
cialized, but  better  able  to  take  advantage  of  the 

36      THE  NAUTILUS 

January  10.  1979 

Vol.  93(1) 

marginal  habitats  where  Marstonia  densities  are 
low  (5  ft-O.B.;  20,  25.  30  ft  -  Y.C.).  Thus  Mar- 
stonia decepta  often  outnumbers  Valvata  tricar- 
inata  in  a  littoral  silt  and  detritus  habitat.  This 
directly  contradicts  Harman's  (1972)  statements 
as  to  the  substrate  preferences  of  these  two  spe- 
cies, and  demonstrates  the  care  which  must  he 
observed  when  attempting  to  apply  the  findings 
of  those  working  on  inland  lakes  in  contrast  t<i 
those  dealing  with  the  ecology  of  the  Great 


The  authors  express  their  deepest  appreciation 
to  Dr.  Lee  H.  Somars.  Director,  Underwater 
Technology  Laboratory  and  the  Michigan  Sea 
Grant  Program  for  providing  technical  assistance, 
as  well  as  the  compressed  air  required  for  200 
man-hours  of  underwater  work  carried  out  dur- 
ing this  study.  The  cooperation  of  the  Omena- 
Traverse  Yacht  Club  is  also  gratefully  acknow- 
ledged. In  addition,  the  assistance  of  our  research 
assistant,  Gregory  Panos,  III,  and  student 
assistants  John  Kerr  and  Larry  Stevens  was  essen- 
tial to  the  completion  of  the  underwater  sampling. 
This  research  was  supported  by  a  grant  from  the 
University  of  Michigan-Flint  Faculty  Research 
and  Special  Projects  Committee. 


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Lake  Michigan  macrobenthos.  Limnology  and  Oceanography 

11:  .576-583. 


Dorothy  Blanchard 

2014  (leddes  Avenue 

Ann  Arbor,  Michigan  48104 


Lowell  L.  Getz 

Department  of  Ecologv',  Ethology  and  Evolution 

University  of  Illinois,  Urbana,  Illinois  (ilSOl 

The  North  American  distribution  of  the  in- 
troduced European  slug,  Ariati  t^ubfiisais 
(Draparnaud),  has  been  described  by  Chichester 

and  Getz  (1968.  1969).  Getz  and  Chichester  (1971) 
and  Getz  (1974).  In  general,  the  species  occurs 
throughout     northeastern     United     States     and 

Vol.  93(1) 

January  10, 1979 

THE  NAUTILUS      37 

southeastern  Canada,  in  the  vicinity  of  Washing- 
ton, D.  C,  and  in  the  Kipawa  Reserve  in  eastern 
Canada.  The  latter  record  represents  the  furthest 
westward  locality  previously  known  for  the 
species.  A  recent  discovery  of  A.  mbfuscus  in 
Ann  Arbor  and  Allen  Park,  Michigan,  is  there- 
fore worthy  of  note.  It  extends  the  known  range 
of  the  species  to  include  the  Great  Lakes  region. 

Specimens  of  the  species  were  first  found  by 
the  senior  author  in  her  yard  located  within  the 
city  limits  of  Ann  Arbor.  Subsequent  investiga- 
tions revealed  the  species  to  be  present  in  some, 
but  not  all,  adjacent  yards,  as  well  as  in  Allen 
Park,  a  suburb  of  Detroit.  It  has  not  been  re- 
ported elsewhere  in  the  Ann  Arbor  or  Detroit 
area,  however.  All  individuals  collected  were 
bright  orange  and  resemble  Color  Form  Three  as 
described  by  Qiichester  and  Getz  (1969). 

The  Blanchard's  yard  contains  extensive  un- 
cultivated planting  of  native  and  introduced 
species  of  herbaceous  plants,  shrubs  and  trees. 
Arion  fasciattis  (Nilsson)  has  been  present  in  the 
yard  for  years,  but  .4.  ftuhfmcus  was  first  noticed 

in  1973.  It  is  not  known  how  the  species  became 
established  in  Ann  Arbor;  most  dispersal  of 
European  slugs  apparently  occurs  during  trans- 
jiort  of  nursery  stock  (Chichester  and  Getz,  1969). 
In  all  regions  except  Michigan  and  Washington, 
D.  C,  A.  subfuscus  occurs  in  natural  woodland 
habitats  as  well  as  in  association  with  human 
habitation.  Chichester  and  Getz  (1969)  have 
predicted  that  A.  subfusctts  will  become 
established  in  natural  habitats  throughout  most 
of  North  Central  United  States  and  South  Cen- 
tral Canada. 


Chichester.  L.  F.  and  L.  L.  Getz.  1968.  Terrestrial  slugs.  The 

Biologist  5<i:14S-im. 
.  1969.  The  zoogeography  and  ecology  of  arionid 

and    limacid    slugs    introduced    into    Northeastern    North 

America.  Malacologia  7:313-.346. 
Getz.    L.    L.    1974.    Arion    .mbfuscus    in    the    vicinity    of 

Washington,  D.  C.  The  Nautihts  88:66. 
Getz,  L.  L.  and  L.  F.  Chichester.  1971.  Introduced  Slugs.  The 
Biologist  53:118-12:1. 


David  Pool  and  Jack  D.  McCullough 

Department  of  Biology 

Stephen  F.  Austin  State  University 

Nacogdoches,  Texas  75962 

Specimens  of  the  Asiatic  Clam,  Corbicula 
manileriftis  (Philippi),  were  collected  on  several 
dates  during  1977  from  Lake  of  the  Pines  Reser- 
voir in  the  Big  Cypress  River  Basin,  Texas,  and 
from  Murvaul  Reservoir  in  the  Sabine  River 
Basin,  Texas.  The  species  has  not  been  previously 
reported  fi'om  either  reservoir.  Specimen  at  Lake 
of  the  Pines  Reservoir  were  collected  approx- 
imately one  kilometer  from  the  dam  at  a  depth  of 
less  than  one  meter,  on  substrates  of  sand,  fine 
gravel  and  very  hard  packed  red  clay.  Collections 
at  Mur\aul  Reservoir  were  made  approximately 
100  meters  from  the  dam  in  a  substrate  of  sand, 
at  water  depths  also  not  greater  than  one  meter. 
While  the  population  densities  of  the  clam  were 
great  in  both  reservoirs,  the  largest  numbers 
were   found   at   a   depth   of  approximately   one 

meter  during  the  summer  months,  and  at  the 
water's  edge  during  the  winter  months. 

The  mean  values  for  physico-chemical  para- 
meters determined  during  1977  (Table  1.)  indi- 
cate both  reservoirs  have  good  water  quality, 
and  the  fertility  of  both  bodies  of  water  are 
classed  as  mesotrophic.  Preserved  specimen  have 
been  deposited  in  the  Invertebrate  collection  at 
Stephen  F.  Austin  State  University. 

TABLE  1.  Meciri  values  for  physico-chemical  parameters  re- 
corded for  Lake  of  the  Pines  and  Murvaul  Reservoirs 
during  1977. 





















Lake  of 
the  Pines 









38      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 


J.  Roy  Robertson 

University  of  Georgia 

Marine  Institute 

Sapelo  Island,  Georgia  31327 


The  occurrence  of  the  crystalline  style  in  an  intertidal  population  of  the  mud 
snail,  Ilyanassa  obsoleta,  7vas  found  to  be  correlated  mth  the  stage  of  the  tide.  At 
bnv  tide  irhen  the  snails  were  exposed  almost  no  individuals  sampled  possessed 
styles,  while  during  high  tide  when  the  snails  were  covered  almost  all  individuals 
sampled  possessed  styles.  The  presence  or  absence  of  a  style  occurred  concomi- 
tantly with  the  presence  or  absence  of  fond  in  the  digestive  tract.  These  observa- 
tions suggest  that  I.  obsoleta  individual  can  possess  cyclical,  discontinuous  feeding 
rhythms,  .'similar  to  those  that  have  been  observed  in  intertidal  bivalves  and  one 
other  gastropod  species. 

The  digestive  processes  of  certain  intertidal 
bivalve  species  and  the  marine  pulmonate 
gastropod,  Amphibola  crenata,  from  New 
Zealand,  have  been  shown  to  be  cyclical  and  cor- 
related with  the  state  of  the  tide  (Morton  1956; 
Morton  1971,  1973  1975a,  1975b,  1977;  Bernard 
1973;  Langton  and  Gabbott  1974).  In  particular, 
the  studies  on  intertidal  bivalves  have  shovra  that 
the  crystalline  style  dissolves  when  the  animals 
are  exposed  at  low  tide  and  reforms  when  they 
are  subsequently  inundated.  Although  the  mud 
snail,  Eyanassa  obsoleta  (Say),  is  a  member  of  the 
typically  carnivorous,  rachiglossan  Gastropoda,  it 
is  primarily  a  deposit  feeder  (Scheltema  1964).  As 
an  adaptation  to  this  mode  of  foraging,  /.  obsoleta 
possesses  a  crystalline  style  which  aids  in  the 
digestion  of  microflora  inhabiting  the  ingested 
substrate  (Brown  1969).  This  note  presents 
evidence  for  the  cyclical  dissolution  and  reforma- 
tion of  the  crystalline  styles  belonging  to 
members  of  an  intertidal  population  of  /.  obsoleta 
in  southeast  Georgia. 

Contribution    No.    380    from    the    University   of   Georgia 
Marine  Institute. 


On  November  18  and  19,  1977,  /.  ob.wleta  in- 
dividuals were  collected  during  various  tidal 
stages  in  a  slough  located  on  the  eastern  side  of 
Sapelo  Island,  Georgia.  Appro.ximately  the  same 
tidal  level  of  the  shore  was  sampled  at  each 
sampling  period.  The  maximum  depth  of  water 
during  subtidal  sampling  periods  was  30  cm. 

Sampling  was  done  by  placing  a  line,  marked 
at  one  meter  intervals,  parallel  to  the  shore  line. 
At  randomly  selected  intervals  10  X  10  cm, 
square  quadrats  were  inserted  into  the  substrate. 
All  of  the  snails,  buried  or  on  the  surface,  were 
removed  from  each  quadrat  sampled.  Enough 
quadrats  were  sampled  so  that  the  total  number 
of  snails  collected  at  each  sampling  period  ex- 
ceeded 50.  Fifty  snails  were  immediately  selected 
at  random  from  the  main  sample.  Each  specimen 
was  processed  in  the  field  according  to  the  follow- 
ing protocol:  1)  shell  length  was  determined,  2) 
snail  was  carefully  removed  from  its  shell  by 
fracturing  the  shell  with  a  portable  vise,  3)  style 
sac  was  opened  with  fine  forceps  and  the 
presence  or  absence  of  a  style  was  noted,  4)  snail 
was  placed  in  vial  containing  acid  Bouin's  fix- 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      39 

ative.  The  total  time  from  collection  to  final  pro- 
cessing did  not  exceed  45  minutes.  The  contents 
of  the  digestive  tracts  of  preserved  snails  were 
determined  later  in  the  laboratory. 


Figure  1  shows  that  the  occurrence  of  the 
crystalline  style  in  the  study  population  is 
definitely  correlated  with  the  tidal  cycle.  Diel 
variations  in  temperature  and  light  do  not  ap- 
pear to  modif>'  this  correlation.  Air  temperatures 
ranged  fi'om  24°C  in  the  daytime  to  VZ'C  just 
before  sunrise  while  water  temperatures  varied 
between  19°  -  15°C.  The  lengths  of  the  snails 
sampled  ranged  from  17-21  mm,  indicating  that 
the  population  under  investigation  comprised  on- 
ly mature  adults  (Scheltema  1964). 

The  presence  of  the  crystalline  style  in  /.  ob- 
soleta  is  correlated  with  the  type  of  food  eaten 
(Brown  1969).  The  style  is  absent  in  snails 
feeding  actively  on  the  flesh  of  animals  while  it 
is  invariably  present  in  those  snails  ingesting 
sandy  or  muddy  substratum.  In  this  study  all  of 
the  snails  with  styles  had  mud  present 
throughout  their  digestive  tracts  while  the  caecae 
and  style  sacs  of  the  snails  which  did  not  possess 
styles  were  devoid  of  any  type  of  food.  In  some  of 
the  latter  snails,  mud  was  found  in  the  posterior 
portions  of  the  intestine  and  the  rectum. 


I  50 

*  40- 

i  =0 


w  20- 

Mvai  of  tranMci 

I        I       I        I 

leoo     zooo 

^tH — I — I — I — I    I    1 

2200   2400   0200   0400   0600   0800 

FIG.  1.  Occurrence  of  the  crystalline  style  in  an  intertiiM 
population  of  Dyanassa  obsoleta.  Upper  curve  represents  tidal 
cycle  urith  horizontal  line  indicating  position  of  sampling 
tnmsect  relative  to  tide.  Arrows  indicate  time  sample  taken. 

Thus  the  correlation  of  the  occurrence  of  the 
crystalline  style  with  the  tidal  cycle  in  the 
population  investigated  appears  to  reflect 
cyclical,  discontinuous  feeding  activities  similar 
to  those  noted  previously  for  bivalves  and  the 
mud-dwelling,  marine  pulmonate,  Amphibola 
erenata.  The  results  of  the  present  study  comple- 
ment those  showing  that  the  locomotor  activity  of 
/.  obsoleta  is  ma.ximum  during  periods  of  high 
tide  and  minimum  during  periods  of  low  tide 
(Stephens,  Sandeen  and  Webb  1953). 

While  this  study  was  restricted  to  a  single 
population  of  mud  snails  and  one  sampling  date, 
it  does  show  that  /.  obsoleta  individuals  can 
possess  discontinuous  feeding  rhythms  correlated 
with  the  tidal  cycle.  Further  work  needs  to  be 
done  on  the  seasonal  variability  of  foraging 
rhythms  (Morton  1975b,  1977)  as  well  as  the  ef- 
fects of  substrate  type,  resource  density  and  size 
of  individual  on  feeding  patterns. 

It  is  interesting  to  note  that  the  feeding  cycle 
of  the  marine  pulmonate,  Amphibola  erenata,  is 
qualitatively  different  from  that  of  /.  obsoleta. 
While  the  latter  restricts  its  feeding  activities  to 
periods  when  it  is  covered  by  the  tide,  Amphibola 
forages  primarily  during  low  tide  or  high  tides 
occurring  at  night  (Morton  1975b).  These  dif- 
ferences may  reflect  different  adaptations  to 
predation  by  visually  orienting  predators  which 
follow  the  incoming  tide  (e.  g.  crabs  and  fish). 
The  lack  of  operculum  may  make  it  adaptive  for 
Amphibola  to  bury  in  the  substrate  when  aquatic 
visual  predators  are  most  active  (high  tide  during 
the  day). 

Ilyanassa,  on  the  other  hand,  possesses  both  a 
durable  shell  and  an  operculum.  These  attributes 
might  provide  sufficient  protection  from  preda- 
tion to  allow  the  snail  to  forage  when  aquatic 
predators  are  active.  The  factors  limiting  the 
'  foraging  activity  of  Eyanassa  to  periods  when 
they  are  covered  with  water  may  be  desiccation 
stress  (Schaefer,  Levin  and  Milch  1968;  Schaefer, 
Milch  and  Levin  1968)  or  the  need  to  ingest  a 
substrate  with  a  sufficiently  high  moisture  con- 
tent to  facilitate  digestion. 

40      THE  NAUTILUS 

January  10, 1979 

Vol.  93  (1) 



Bernard.  F.  R.  1973.  Crystalline  style  formation  and  function 

in  the  oyster  Cras.tostren  giyax  (ThunberR.  119^).  <>}iheli<i 

Brown,  Stephen  C.  1969.  The  structure  and  function  of  the 

digestive  system  of  the  mud  snail  Nassarim  obsolettis  (Say). 

Malacoloyia  9: -147-500. 
Langton.  R.  W.  and  P.  A.  Gabbott.  1974.  The  tidal  rhythm  of 

extracellular  digestion  and  response  to  feeding  in  (htrea 

edulis  L.Mnr.  Rml  24:181-187. 
Morton.  B.  S.  1971.  The  daily  rhythm  of  feeding  and  digestion 

in  (Mri'a  tdulis.  Binl.  Jaur.  Linn.  Sik:  3:329-:M2. 
.  197.3.  A  new  theop,'  of  feeding  and  digestion  in 

filter -feeding  Lamellibranchia.  Afoyacvi/oi/ia  14:63-79. 

.    197.58.   The   diurnal    rhythm    and    the    feeding 

responses  of  the  Southeast  Asian  mangrove  bivalve,  Gelmna 
proxima  Prime  1864  (Bivalvia:  Corbiculacea).  Forma  et 
Futwtio  8:405-418. 

.  197.5).  The  seasonal  variation  in  the  feeding  and 

digestive    cycle    of    Amphibola    crenatn    (Martyn     1784) 
(Gastropoda:  Pulmonata).  Forma  et  Functio  8:17.5-190. 

_.  1977  The  tidal  rhvthm  of  feeding  and  digestion 

in  the  Pacific  oyster,  Crassiostrea  gigas  (Thunberg).  Jour. 
Krp.  Mar.  Biol.  Ecol.  26:135-141. 

Morton,  J.  E.  19.56.  The  tidal  rhythm  and  action  of  the 
digestive  system  of  the  lamellibranch  iMsaea  rubra.  Jour 
Mar.  Biol.  Ass.  U.  K.  35:.563-.586. 

Schaefer,  C.  W.,  Peter  Milch  and  N.  L.  Ixjvin.  1968.  Death 
from  desiccation  in  the  mud-snail.  Sassanus  ohsoletus:  ef- 
fect of  temperature,  ne  Nautilus  81: 109-1 14. 

Schaefer,  C.  W.,  N.  L.  Levin  and  Peter  Milch.  1968.  Death 
from  desiccation  in  the  mud-snail.  NassariiLs  ohsoletus:  ef- 
fects of  size.  The  NautUw^  82:28-31. 

Scheltema.  Rudolf  S.  1964.  Feeding  habits  and  growth  in  the 
mud-snail  Nassarius  obsolet us.  Chesapeake  Sri.  5: 161  - 166. 

Stephens,  G.  C,  M.  I.  Sandeen  and  H.  M.  Webb.  19.53.  A  per- 
sistent tidal  rhj-thm  of  activity  in  the  mud  snail  A'a.s,sa  ob- 
soleta.Anat.Ker.  117:635. 


Edward  B.Hatfield' 

Rosenstiel  School  of  Marine  and  Atmospheric  Science 

4600  Rickenbacker  Causeway 

Miami,  Florida  33149 


Lrnfjth  meaavrements  were  made  on  indii'idiiah  o/ Anachis  avara  maintnined  in 
the  laboratory  on  carrion,  epihiota  from  neaip-asfi  blades.  o}yanics  in  the  sediment, 
and  on  organics  from  a  flow-through  neawater  system  as  a  control.  Snails  grew 
52%  as  much  on  epibiota  as  on  canion,  and  showed  some  growth  with  sediment  or 
water  column  organics  as  their  food.  Epibiota  are  probably  a  significant  souive  of 
food  for  A.  avara  in  the  field. 

References  regarding  feeding  in  columbellid 
gastropods  show  varied  and  sometimes  contradic- 
tory results  (Puffer  and  Emerson  1953;  Moore, 
1%1;  Marcus  and  Marcus,  1962;  Bandel,  1974). 
This   paper   reports   differences    in    growth    for 

'  Present  address:  Jackson  E^uarine  Laboratory.  University 
of  New  Hampshire,  R.F.D.  #1,  Adams  Point.  Durham,  New 
Hampshire  03824. 

Anachis  avara  (Say)  on  three  separate  food 
sources,  and  reviews  the  available  literature  on 
columbellid  feeding. 


Two  hundred  and  forty  Anax;his  avara  were 
collected  from  a  turtle  grass,  Thalassia 
testudinum    (Konig).   flat   at    Bear   Cut,   Miami, 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      41 

Florida,  during  June,  1975.  These  individuals 
were  measured  and  placed  in  eight  19-liter 
aquaria  with  running  salt  water.  Two  replicates 
were  maintained  with  carrion  (C),  turtle  grass 
with  its  epibiota  (E),  and  particulate  organic 
matter  and  detritus  in  sediment  (D),  as  food 
sources,  with  the  slight  supply  of  particulate 
organic  matter  in  the  flow-through  water  used  as 
control  (W).  No  attempt  was  made  to  measure 
the  amount  of  food  provided  or  the  amount  of 
organic  matter  entering  with  the  running  water. 
It  was  assumed  that  the  120  grass  blades  and  the 
4  cms.  of  sediment  in  the  separate  pairs  of 
aquaria  provided  the  relative  amounts  of  their 
associated  foods  available  in  the  habitat.  The  tur- 
tle grass  and  sediment  were  changed  weekly.  Car- 
rion was  provided  twice  weekly  for  six-hour 
periods,  and  all  eight  aquaria  were  cleaned 
thoroughly  at  weekly  intervals.  The  length  of 
each  snail  was  measured  to  the  nearest  0.01  mm 
with  vernier  calipers  every  fourteen  days  for  a 
period  of  six  weeks.  Differences  between  mean 
sizes  were  tested  by  a  two-level  nested  ANOVA 
at  the  0.05  alpha  level  and  by  the  Student- 
Newman-Keuls  non-parametric  test  (Sokal  and 
Rohlf,  1969). 


Table  1  shows  no  difference  in  mean  lengths  of 
the  snails  in  the  eight  aquaria  at  the  beginning 
of  the  experiment.  After  28  days,  three  separate 
groupings  by  mean  size  were  recognizable.  Snails 
which  were  fed  carrion  grew  the  most;  those  fed 
grass  blade  epibiota  grew  next  best;  and  those  fpd 
sediment  organics  and  detritus  grew  the  least, 
the  latter  being  grouped  with  the  snails  from  the 
control  aquaria.  The  differences  in  size  which  oc- 
curred are  shown  in  Figure  1.  Significant  results 
from  this  experiment  are  that:  1)  growth  oc- 
curred in  all  tanks,  including  the  controls  where 
the  only  food  source  was  particulate  organic  mat- 
ter entering  through  the  flow-through  seawater 
system ;  2)  snails  feeding  on  the  epibiota  from  the 
grass  blades  grew  52%  of  the  amount  that  snails 
feeding  on  carrion  did.  Depending  on  relative 
availability  of  epibiota  and  carrion  in  the  field, 
this  latter  result  suggests  that  these  epibiota  are 
an  important  food  source  for  .4.  avara  in  seagrass 

TARLE  1.  Mean  iemjth  (mm)  «/ Anachis  avara  and  renults  of 
a  Studcnt-Newman-Ki'iiU  analyxif  offeediiuj.  Tlic  fond  types 
connected  by  each  bar  contain  snaih  of  the  name  statistical 
mean  length. 


(days)  Length    (mm) 







































C  =  carrion;  E  =  epibiota;  D  =  detritus;  W  =  organics 
from  seawater  (controls);  *  =  no  data;  1  &  2  =  replicates  of 
each  food  type. 


Several  food  sources  are  available  to  Anachis 
avara  at  Bear  Cut.  Many  of  the  mean  3291 
seagrass  blades  per  m^  are  encrusted  with  various 
kinds  of  epibiota  (Humm,  1964;  Meyers  et  ai, 
1965;  and  personal  observations).  These  epibiota 
include  polychaetes,  hydroids,  tunicates,  sponges, 
bryoza,  and  protozoa,  as  well  as  diatoms,  blue- 
greens  and  several  species  of  red,  green,  and 
brown  macroalgae.  No  attempt  was  made  to  dif- 
ferentiate between  epifauna  and  epiflora  as  food 
sources  for  Anachis  avara.  Carrion,  such  as  dead 
spider  crabs,  fish,  and  the  large  bivalve,  Atrina 
riyida.  was  visibly  entrapped  in  the  sediment. 
Particulate  organics  and  detritus  were  also  pre- 
sent in  the  habitat  substratum. 


C   = 


E  = 




D   = 



■J  8.5   . 

W   = 





""^                    E 





0  14  28  42 

TIME  (days) 

FIG.    \.  Mean    lengths    (mm)   of   Anachis    avara   fur    two 
replicates  of  each  of  three  food  types  and  a  control. 

42      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

The  amounts  and  availability  of  the  different 
f(x)d  sources  of  Anachis  avara  at  Bear  Cut  prob- 
ably differ.  A.  avara  is  the  only  abundant 
sizeable  gastropod  prazer  at  Bear  Cut,  aside  from 
the  micromollusks,  Bittium  varium,  Tricolia  af- 
finis,  and  several  species  of  Caecum.  Only  occa- 
sional individuals  of  other  columbellid  species  or 
other  gastropods  such  as  Turbo  castaneus  or 
Astraea  americana  were  collected.  Therefore, 
although  some  overlap  in  food  choice  may  exist 
between  A.  avara  and  species  from  other  phyla, 
such  as  caridean  shrimp,  competition  for  the 
epibiota  is  not  thought  to  be  intense.  The  high 
productivity  and  continuous  presence  of  epibiota, 
and  the  probable  low  competition  for  this  fauna 
and  flora,  make  this  source  of  food  highly 
available  to  A.  avara. 

Carrion  is  also  available  to  Anachvi  avara,  but 
it  is  also  consumed  by  swimming  crabs,  Calli- 
nectes  sapidus  and  Callinectes  oniatu.%  juvenile 
spiny  lobsters,  Panularus  argus,  stomatopods, 
several  species  of  fish  and  other  faunal  groups.  I 
placed  pieces  of  the  bivalve,  Chione  cancellata,  in 
the  habitat  and  witnessed  several  Callinectes  cap- 
ture them  prior  to  observable  reaction  by  A. 
avara.  Particulate  organic  matter  from  the  sea- 
water  and  sediment  is  also  available;  however, 
results  of  the  laboratory  experiment  suggest  this 
is  only  a  minimal  source  of  food. 

Anachis  avara  probably  feeds  opportunistically, 
and  this  may  be  typical  of  many  species  of  the 
family  Columbellidae.  In  the  laboratory-,  I  have 
seen  Anachis  avara  feed  on  moribund  Tagelus 
divims,  a  small  gaping  bivalve,  but  not  on 
tightly-closed  Tellina  texana  or  Macoma  cenna. 
Scheltema  (1969)  maintained  Anachis  avara  on 
clam  meat  in  the  laboratory.  Puffer  and  Emerson 
(1953)  reported  Amwhis  avara  semiplicata  from 
an  oyster  reef  off  central  Texas  as  a  herbivore. 
Moore  (1961)  suggested  that  Anachis  avara  from 
Port  Aransas,  Texas,  preys  on  young  oysters. 
Because  Anachis  avara  does  not  extend  from  the 
Atlantic  into  the  Gulf  of  Mexico  (Scheltema, 
1968;  and  Radwin,  1977),  the  species  reported  by 
Puffer  and  Emerson  (1953)  and  Moore  (1961)  is 
probably  Anachis  semiplicata  (Radwin,  1977:  and 
Moore,  pens.  com.).  However,  the  status  of  the 
western  Gulf  of  Mexico  species  is  not  clear 
(Scheltema,    1968).    Individuals    of   Anachis 

semiplicata  from  Sarasota,  Florida,  and  of 
Anachvi  avara  from  Bear  Cut  lived  and  spawned 
in  the  laboratory  on  a  diet  of  clam  and  fish  meat. 

Differences  in  foods  reported  for  several  col- 
umbellid species  are  partly  the  result  of  in- 
complete feeding  investigations  and  secondary 
reports.  Marcus  and  Marcus  (1962)  found  algae  in 
the  gut  of  Columbella  mercatoria.  Bandel  (1974) 
reported  spawning  for  individuals  of  this  species 
maintained  in  the  laboratory  on  both  algae  and  meat.  I  saw  capsules  produced  in  aquaria  by 
individuals  of  this  species  that  had  been  fed  clam 
and  fish  meat  exclusively.  I  also  saw  Columbella 
rmticoides  spawn  in  the  laboratory  on  the  same 
clam  and  fish  meat  diet.  Marcus  and  Marcus 
also  found  algae  in  the  gut  of  this  species. 
Miller  (1974)  stated  that  most  columbellids  are 
attracted  to  dead  and/or  injured  prey,  although 
members  of  the  genus  Columbella  probably  eat 
primarily  plant  material.  The  conclusion  from 
Marcus  and  Marcus  (1962)  that  the  two  above 
species  of  Columbella  are  solely  herbivorous  is 
not  correct. 

From  a  detailed  study  of  the  anatomy  of  eight 
columbellid  species,  Marcus  and  Marcus  (1962) 
included  that  as  a  group  the  columbellids  are 
general  feeders.  Marcus  and  Marcus  (1962)  found 
recognizable  parts  of  polychaetes,  Crustacea,  and 
colonial  ascidians  in  the  alimentary  tract  of  six 
species  of  columbellids.  Raeihle  (1969)  stated  that 
newly  hatched  Nitidella  ocellata  (now  Mitrella 
ucellata  (see  Abbott,  1974))  and  an  unidentified 
Anachis  sp.  fed  on  crushed  Mytilus  edulis  spat. 
Bandel  (1974)  reported  that  Nitidella  laevigata 
eats  Sargassum  as  well  as  meat;  that  Mitrella 
argus  and  Anachis  obesa  eat  hydroids  but  also 
feed  on  pieces  of  clam  and  fish  meat;  and  that  six 
other  columbellid  species  feed  on  fresh  meat  in 
the  laboratory.  Spight  (1976)  mentioned  that 
some  columbellids  feed  on  freshly  killed  crabs, 
limpets,  and  chitons  in  the  laboratory-.  I  have  also 
maintained  Mitrella  ocellata  Mitrella  bmata, 
and  Nitidella  moleculina  in  the  laboratory  on 
fresh  meat  from  several  species  of  fish  and 
bivalves.  Fretter  and  Graham  (1962)  point  out 
that  the  superfamily  Buccinacea  is  carrion- 
feeding,  rather  than  predatory,  as  its  members 
have  lost  the  accessory  salivary  glands  and  boring 
organ    necessary   for   that   activity.    In   general. 

Vol.  93(1) 

January  10, 1979 

THE  NAUTILUS      43 

foods  among  the  columbellids  vary  and  it  is  prob- 
able that  at  least  some  species  utilize  varied  plant 
and  animal  sources. 

As  no  analysis  was  made  of  what  Tlmla.'^Kia 
epibiota  or  sediment  organics  and/or  detritus 
that  Anachis  avara  fed  on  during  the  laboratory 
experiment,  it  cannot  be  concluded  whether  this 
species  is  carnivorous  or  omnivorous.  Leathern 
and  Maurer  (1975)  refer  to  this  species  as  a  car- 
nivore, but  they  reach  this  conclusion  from 
published  references  (Leathern,  pers.  com.).  To  my 
knowledge  the  results  of  a  discrete  test  of 
whether  Anachis  avara  is  carnivorous  or  om- 
nivorous have  not  been  published.  I  conclude  that 
Anarchis  avara  can  obtain  nutriment  from  other 
than  carrion,  particularly  by  grazing  epibiota  off 
turtle  grass  blades,  but  also  from  particulate 
organics  in  the  sediment  and  from  the  water  col- 
umn. Where  there  is  a  plentiful  source  of  food,  I 
doubt  that  food  is  a  limiting  resource  for  this 
species  in  the  seagrass  flats  near  Miami,  Florida. 


This  work  was  completed  as  part  of  a  disserta- 
tion in  partial  fulfillment  of  the  requirements  for 
the  degree  of  Doctor  of  Philosophy  at  the  Univer- 
sity of  Miami,  Miami,  Florida.  I  would  like  to 
acknowledge  the  help  of  members  of  my  commit- 
tee of  which  Drs.  H.  B.  Moore  and  D.  R.  Moore 
critically  read  the  manuscript. 


Abbott.    R.    T.    1974.    American    Seashelk.    Van    Nostrand 

Reinhold  Co.,  New  York.  66,3  pp. 
Bandel,  K.   1974.  Spawning  and  development  of  some  Col- 

umbellidae  from  the  Caribbean   Sea  of  Colombia  (South 

America).  The  Fe/iser  16(3):271-282. 

Spetimen  Shells 

Offering  microscopic  and  miniature  (to  ' :  inch)  shells  from 
the  Florida  Keys,  with  accurate  locality  data.  Also  unsorted 
grunge;  write  for  list. 

Margaret  Teskey 

P.  0.  Bnx  27S 

BiijPineKeii.FI  -imi 

Fretter.    V.    and    A.    Graham.    1%2.    Rritijih    Pmxohranch 

A/(i//H,sr.s-;    Their  Functimml   Anatomy  and   Eriiliigy.    Ray 

S(x.'iety.  London. 7.5.5 pp. 
Hiunm,   H.  J.   1964.   Epiph>-tes  of  the  sea  grass.  Vialaxsia 

trxtiidinum   in   Florida.  Btdt.  Mar.  Sri.   Gulf  and  (hrih. 

Leathern.   W.   and   D.   Maurer.    U)7.5.   The  distribution   and 

ecology  of  common  marine  and  estuarine  gastropods  in  the 

Delaware  Bay  area.  Nautihi.'^  89(3):73-79. 
Mareas,  E.  and  E.  Marcus.  1962.  Studies  on  Columbellidae. 

Bol.    Far.    Filo.'t.    Cien.    Let.    Univ.    San    Pmdo.    261(Zool 

Meyers.  S.  P.,  P.  A.  Orpurt.  J.  Simms  and  L.  L.  Boral.  19&5. 

Thalassiomycetes  VIL  Observations  on  fungal  infestation  of 

turtle  gi-ass,  Thalassia  testudinum  Konig.  Bull.  Mar.  Sri. 

Miller,  A.  C.  1974  A  comparison  of  gastropod  species  diversity 

and  trophic  structure  in  the  rocky  intertidal  zone  of  the 

temperate  and  tropical  west  Americas.  Ph.D.  Diss..  Univ.  of 

Oregon.  143  pp. 
Moore,  D.  R.  1961.  The  marine  and  brackish  water  Mollusca  of 

the  state  of  Mississippi.  G«i/i?e.'i.  Rep.  l(l):l-58. 
Puffer,  E.  L.  and  W.  K.  Emerson.  195,3.  The  moUuscan  com- 
munity of  the  oyster-reef  biotope  on   the  central   Texas 

coast.  Jw/r.  nfPaeleo.  27(4):537-.544. 
Radwin,  G.  E.  1977.  The  family  Columbellidae  in  the  western 

Atlantic.  Part  Ila:  The  Pyreninae.  The  VWi:g.'r20(2):119-133. 
Raeihle,  D.  1969.  Egg  cases  of  Nitidella  ocellata  Gmelin  and 

an  Anachix.  Ann.  Report  Amer.  Malaeol.  t'mon. :25-26. 
Scheltema,  A.  H.  1968.  Redescriptions  of  Anachis  avara  (Say) 

and   Anachis   translirata   (Ravenel)   with   notes   on   some 

related    species    (Prosobranchia.    Columbellidae).   Breinora 

.  1969.  Pelagic  larvae  of  New  England  gastropods. 

IV.  Anachis  translirata  and  Anachis  avara  (Columbellidae, 
Prosobranchia).   Vie  et  Milieu.  Serie  A:   Biologie  Marine 

Sokal.  R.  R.  and  F.  J.  Rohlf.  1969.  Biometry  W.  H.  Freeman 

and  Co.,  San  Francisco.  776  pp. 
Spight.  T.  M.  1976.  Censuses  of  rocky  shore  prosobranchs  from 
Washington  and  Costa  Rica.  The  Veliger  18(3):309-317. 


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44      THE  NAUTILUS 

January  10, 1979 

Vol.  93  (1) 



Jean  Ann  Nichols  and  J.  Roy  Robertson 

University  of  Ge^irgia 

Marine  Institute 

Sapelo  Island,  GA  31327 


Exclusion  experiment's  conducted  with  the  mud  snail,  Ilyanassa  obsoleta  (Say),  in 
nematode  and  benthic  diatom  communities  showed  that  the  areas  devoid  of  snails  had 
higher  densities  of  both  benthic  diatoms  and  Pseiidotheristid  nematodes  than  the  con- 
tiguous control  area.  We  suggest  that  the  increase  in  the  diatmn-eating 
Pseudotheristus  s-p.  in  the  exclusion  plot  was  a  behavioral  response  to  increased 
diatom  densities,  thus  demonstrating  an  indirect  trophic  interaction  between  a 
moUuscan  macrofaunal  herbivore  and  a  nematode  member  of  the  meiofaunal  com- 

The  mud  snail  Uynassa  obsoleta  (Say)  is  an 
ubiquitous  organism  in  the  intertidal  region, 
ranging  from  the  Gulf  of  St.  Lawrence  to  north- 
eastern Florida  on  the  east  coast  of  North 
America.  It  is  an  omnivorous  depositfeeder,  ap- 
parently subsisting  almost  entirely  on  ingested 
sand  and  mud  and  associated  organisms  (Brown, 
1969).  The  animal  has  been  the  subject  of  many 
experimental  and  descriptive  studies,  but  little 
work  has  been  concerned  with  the  influence  of  /. 
obsoleta  on  biological  components  of  its  environ- 
ment. As  a  portion  of  a  project  to  develop  field 
methods  for  analysis  of  possible  trophic  links  be- 
tween faunal  groups,  we  initiated  a  series  of  ex- 
periments on  an  intertidal  salt  marsh  creekbank 
at  Sapelo  Island,  Georgia.  Results  from  these  ex- 
periments indicate  that  when  the  eastern  mud 
snail  Hyanai^sa  obsoleta  (Say)  is  excluded  from  an 
area,  meiofaunal  nematode  populations  respond 
to  increases  in  diatom  population  and  that  this 
response  is  most  probably  a  result  of  feeding 

Wetzel  (1976)  demonstrated  that  Ilyanassa  ob- 
soleta (Say)  can  ingest  and  assimilate  benthic 
diatoms.  In  addition.  Pace  (1977)  has  shown  that 
if  /.  obsoleta  (Say)  is  excluded  from  an  area  of 

'  Contribution  No.  379  from  the  University  of  Georgia  Marine 

the  intertidal  creekbank  in  the  salt  marsh,  both 
chlorophyll  a  and  ATP  concentrations  in  the  top 
centimeter  of  sediment  show  significant  increases 
within  twenty-four  hours.  After  five  days  the 
concentrations  of  these  substances  increased 
significantly  within  the  2-5  cm  layer  of  sediment. 
However,  he  did  not  determine  the  actual  cause 
of  these  increases.  Since  up  to  90%  of  total  sedi- 
ment ATP  can  be  attributed  to  nematodes 
(Sikora  et  al..  1977),  it  is  possible  that  the  dif- 
ference in  ATP  concentrations  observed  by  Pace 
(1977)  reflected  significant  changes  in  the 
nematode  community.  We  utilized  similar  e.xclu- 
sion  techniques  to  obtain  diatom  blooms  with  the 
intent  of  studying  numbers  of  individuals  rather 
than  lumped  sums  of  chlorophyll  a  and  ATP. 

The  study  area  was  the  same  as  used  by  Pace 
(1977).  The  intertidal  sediment  is  80%  silt-clay.  In 
July,  the  time  of  this  e.xperiment,  the  average 
density  of  /.  obsoleta  (Say)  is  1500  m  ^  A  one 
meter  square  area  was  enclosed  with  '  4"  (0.635 
cm)  hardware  cloth  50  cm  high  and  extending  3 
cm  into  the  sediment.  Snails  were  removed  from 
the  enclosed  area.  One  square  meter  contiguous 
with  the  experimental  area  was  used  as  a  control. 
Just  after  the  water  receded  from  the  area,  3  cm' 
pieces  of  lens  paper  (double  thickness)  were 
placed  in  four  randomly  selected  areas  in  both 

Vol.  93  (1) 

January  10, 1979 

THE  NAUTILUS      45 

the  experimental  and  control  areas.  Small  cages 
were  placed  around  the  lens  paper  in  the  control 
area  to  prevent  disturbance  by  snails  during  col- 
lection of  the  algae.  These  cages  were  in  place  on- 
ly during  collection  of  algae.  After  three  hours 
the  lens  paper  was  collected  and  diatoms  removed 
by  a  method  similar  to  that  of  Eaton  and  Moss 
(1966).  Briefly,  lens  papers  were  heated  with 
sulfuric  acid  and  potassium  permanganate.  They 
were  then  washed  in  distilled  HjO  by  centrifug- 
ing  and  decanting,  transferred  to  vials  and 
brought  to  constant  volume  of  3  ml.  Four  sub- 
samples  (2  X  10"  ml)  from  each  vial  were 
counted  using  a  hemacytometer.  This  method 
may  overestimate  numbers  due  to  cell  breakage 
and  separation  of  valves  (Eaton  and  Moss,  1966) 
but  is  necessary  to  determine  the  species  com- 
position of  the  samples. 

A  ten  cc  syringe  was  used  to  collect  samples  of 
the  nematode  population.  It  was  assumed  that 
nematodes  near  the  surface  of  the  sediment  were 
more  likely  to  be  influenced  by  the  diatom 
populations  than  those  in  deeper  sediments. 
Therefore,  only  the  top  two  centimeters  of  sedi- 
ment were  collected.  Three  samples,  collected  ran- 
domly from  both  the  experimental  and  control 
areas,  were  fixed  with  formaldehyde  (3%  V/V). 
After  twenty-four  hours  in  the  formaldehyde 
solution,  samples  were  rinsed  through  a  45  j/m 
mesh  screen.  Individuals  retained  on  the  screen 
were  counted.  After  dehydration,  glycerine  slide 
mounts  were  prepared. 

Data  presented  here  are  from  samples  obtained 
on  day  1  and  day  5  of  the  experiment.  On  both 
days  the  mean  number  of  cells/ cm^  within  the  ex- 
perimental area  was  greater  than  the  control 
area  (Table  1).  ANOVA  tests  of  mean  number  of 
diatom  cells/ cm'  indicate  that  there  were  signifi- 
cant differences  between  the  experimental  and 
control  areas  and  between  days.  The  significant 
interaction  term  is  due  to  the  fact  that  the  in- 
crease in  cell  concentration  from  day  1  to  day  5 
was  greater  in  the  experimental  area  than  in  the 
control  area  (Table  2.). 

The  patchy  distribution  of  nematodes  prevents 
any  meaningful  statistical  analysis  of  the 
numbers  of  organisms  obtained  in  the  samples. 
However,  on  day  1  the  average  number  of 
nematodes  in  all  samples  was  100.  After  five  days 

TABLE  1.  Numbers  of  diatoms  observed. 

Day  1 
Dav  5 

Erperimpitt(d      Cimtrol 
2.93  0.67 

7.12  1.27 

Mean  number  of  cells/an'  X  10' 

the  average  number  of  individuals  in  the  control 
area  remained  at  100.  Average  number  of  in- 
dividuals within  the  experimental  area  had  in- 
creased to  300. 

The  change  in  species  composition  between  day 
1  and  day  5  is  of  great  interest.  Initially,  the 
nematode  populations  were  composed  of  about  fif- 
teen different  families  (several  undescribed 
species  are  represented),  principally  representing 
the  Enoplida  and  Monhysterida  orders.  This 
diverse  distribution  remained  in  the  control  area. 
On  day  5,  70%  of  the  individuals  from  the  ex- 
perimental area  were  Pseudotheristus  sp.  This 
species  represented  only  19%  of  the  population  in 
the  control  area.  The  actual  number  of  non- 
Pseudotheristus  individuals  remained  stable  in 
both  the  experimental  and  control.  Thus,  the  in- 
crease in  numbers  of  individuals  in  the  ex- 
perimental area  was  due  entirely  to  the  presence 
of  Pseudotheristus  sp. 

Information  on  the  generation  time  of  free- 
living  marine  nematodes  is  scarce.  Tietjen  (1969) 
and  Tietjen  and  Lee  (1972,  1973)  have  reported 
minimum  generation  times  of  22  days  under  op- 
timal laboratory  conditions.  Hopper,  Fell  and 
Cefalu  (1973)  report  generation  times  of  1-^4  days 
to  112  days  for  six  free-living  nematode  species 
cultured  from  decaying  mangrove  {Rhizophora 
mangle)  leaves.  Since  the  first  egg  cleavage  re- 
quires from  six  to  thirty-five  hours  (Hope,  1974), 
it  seems  unlikely  that  reproduction  could  account 
for  the  increase  in  numbers  of  adult  individuals 
observed  during  the  period  of  five  days. 

TABLE  2.  Analysis  of  variance  of  diatom  numbers. 

.SN        df 

)hs            F 



406.4.5    .3 


26:3.12    1 

263.12  47.92 



91.93    1 

91.93  16.65 



.51.41     1 

51.41    9.38 



65.92  12 


SS  =  sum  of  squares;  df  =  degree  of  freedom;  ms  =  mean 

46      THE  NAUTILUS 

January  10, 1979 

Vol.  93(1) 

S^eventy-five  percent  of  the  Pfteudotheri.'^tus  sp. 
contained  diatoms  within  their  guts.  Individuals 
contained  from  two  to  twenty-two  diatom 
frustules.  In  most  cases  chioroplasts  were  visible 
when  the  frustule  was  located  in  the  anterior 
portion  of  the  gut.  but  not  in  the  posterior  posi- 
tion. Diatoms  were  not  found  in  the  guts  of  any 
of  the  other  species  of  nematodes  in  either  the 
control  or  experimental  area. 

While  it  is  possible  that  the  difference  in 
nematode  density  was  because  predation  by  the 
mud  snails,  two  lines  of  evidence  render  this  in- 
terpretation unlikely:  dissection  of  over  thirty  /. 
obsioleta  (Say)  revealed  no  nematodes  in  their 
caecae  and  the  change  in  nematode  density  was 
entirely  due  to  increase  in  the  Pseudothe7i.<itvs 
sp.  population.  It  is  unlikely  that  /.  ohsoleta  (Say) 
individuals  exercise  any  selection  over  the  type  of 
material  ingested  from  the  substrate  (Brown, 
1969).  Therefore,  we  suggest  that  the  increase  in 
Pseudotheristus  sp.  is  a  result  of  competitive 
release,  thus  demonstrating  an  indirect  trophic 
interaction  between  the  macrofaunal  species  R- 
yanassa  ohsoleta  (Say)  and  the  meiofaunal  species 
PsevAotheristns  sp. 


Brown,  S.  C.  1969.  The  structure  and  function  of  the  digestive 

system    of    the    mud    snail    Nassarius    obsoletus    (Say). 

Malacologia  9:447-498. 
Eaton,  J.  W.,  Moss,  B.  1966.  The  estimation  of  numbers  and 

pigment  content   in  epipelagic  algal  populations.  Limnol. 

Oceaniiyr.  11:584-. ^.5. 
Hope,  W.  D.  1974.  Nematoda.  In  Reproduction  of  Marine  In- 

vetiehrntes   Vol.    1.    (Giese.   A.   C.   &   Pearse,   .1.   S..  ed.) 

Academic  Press.  New  York.  pp.  391-470. 
Hopper,  B.  E..  Fell,  J.  W.,  and  C«falu,  R.  C.  1973.  Effect  of 

temperature  on  life  cycles  of  nematodes  associated  with  the 

Mangrove   (Rhizophnra   mangle)   Detrital   System.  Marine 

Bn(/(v.'/ 23:293-296. 
Pace.  M.  L.  1977.  The  effect  of  macroconsumer  grazing  on  the 

benthic  microbial  community  of  a  salt  marsh  mudflat.  MJ^. 

Tliesis.  University  of  Georgia.  Athens,  Georgia.  80  pp. 
Sikora,  J.  P.,  Sikora,  W.  B..  Erkenbrecher.  C.  W.,  and  Coull, 

B.  C.  1977.  Significance  of  ATP.  carbon,  and  caloric  content 

of  meiobenthic  nematodes  in  partitioning  benthic  biomass. 

Marine  Binlogy  44:7-14. 
Tietjen.  .1.  H.  1969.  The  ecology  of  shallow  water  meiofauna  in 

two  New  England  estuaries.  Ckcohiyia  2:2.51-291. 
Tietjen,  J.  H.,  Lee.  J.  J.  1972.  Life  cycles  of  marine  nematodes. 

Oecoloyid  10:167-176. 
.    1973.    Life  history  and   feeding   habits  of  the 

marine    nematode,    Chromaiiora    macrolaimoidex    Steiner. 

Oecologia  12:303-314. 
Wetzel.  R.  L.  1976.  Carbon  resources  of  a  benthic  salt  marsh 

invertebrate,    Nassarius     obsoletus     Say     (Mollusca: 

Na.s.sariidae).  In  Estuarine  Processes.  Vol.  11   (Wiley,  M., 

ed.)  Academic  Press.  New  York.  pp.  293-.308. 






C,  M.  Yonge  and  T.  E.  Thompson 

An   Understandable   Biology   Text 

The  first  modem  book  on  the  biology  of  marine  mollusks 
that  is  of  textbook  quality,  yet  so  beautifully  written 
and  illustrated  that  the  legions  of  amateur  conchologists 
will  readily  absorb  its  wealth  of  information"—/?.  Tucker 
Abbott.  Ph.D. 

Clothbound,   288  pp.,  162  text  figures,  16  plates 
with  18  glorious  color  photographs  $14.9.S 

american  malacologists 

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ISSN  0028-1344 
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Dr.  Arthur  S.  Merrill 
Woods  Hole  Biological  Laboratory 
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Dr.  Donald  R.  Moore 
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Complete  listings  of  the  world's  seashells,  with 
geographical  ranges,  values,  and  World  Size 



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som.  Clench.  Powell.  Ponder  and  many  others 
Formerly  called  Van  Nostrands  Standard 
Catalog  of  Shells  Now  published  by  American 
Ma/aco/og/sts,  Publishers. 

Destined  to  be  a  complete  technical  listing  of  all 
the  living  marine  shells  of  the  world  The  St*n 
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Under  the  editorship  of  Robert  I    L   Wagner  and 
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Tertiary  marine  Mollusca  of  the  world 

Edited  By  R.  Tucker  Abbott 

Monographs  of  Marine  Mollusca  is  a  professional  journal  devoted  to  the  systematics, 
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CULATION (Required  by)  Act  of  October  23,  1962:  Section 
4396.  Title  39.  United  States  Code,  and  postal  regulation 

1.  Title  of  publication;  THE  NAUTILUS. 

2.  Dateof  filing,  September  25. 1978. 

3.  Frequency  of  Issue:  Quarterly  (4  per  year). 

4.  Location  of  known  office  of  publication:  429B  Artfiur 
Drive.  Hockessin,  DE  19707 

5.  Location  of  tfie  Headquarters  of  General  Business 
Offices  of  the  Publishers:  4298  Arthur  Drive, 
Hockessin,  DE  19707. 

6.  Names  and  addresses  of  publisher,  editor,  and 
managing  editor:  Publisher,  American  Malacologists, 
Inc.,  PO.  Box  4208,  Greenville,  DE  19807.  Editor,  R. 
Tucker  Abbott,  PO  Box  4208,  Greenville,  DE  19807 
Business  Manager,  Mrs.  Horace  Burrington  Baker,  11 
Chelten  Rd.,  Havertown,  PA  19083. 

7.  Owner:  American  Malacologists,  Inc  P.O.  Box  4208, 
Greenville,  DE  19807  R  Tucker  Abbott. 

8.  Known  bondholders,  mortgages,  and  other  security 
holders  owning  or  holding  1  percent  or  more  of  total 
amount  of  bonds,  mortgages  or  other  securities: 

Extent  and  Nature  of  Circulation: 






Total     No.     copies     Printed     (Net 





Paid  Circulation 

1.  Sales  through  dealers  and  car- 
riers, street   vendors  and  counter 




2.  Mail  subscriptions 




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Free       Distribution       (including 
samples)  by  mail  carrier  or  other 





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Office   use,   left-over,   unaccounted 

and  back  start  subscription  copies 




Total    (Sum    of   E&F)-should   equal 

net  press  run  shown  in  A. 

1,000       1,000 

I  certify  that  the  statements  made  by  me  above  are  cor- 
rect and  complete, 
(signed)  R.  Tucker  Abbott,  Editor 



Volume  93,  numbers  2-3  —  April  23,  1979 

ISSN  0028-1344 


Bernadine  Barker  Baker 

A  Tribute  Upon  her  Retirement '^ 

Melbourne  R.  Carriker  ,  ,    .     ,o,        .  \n 

Ultrastructural  Effect  of  Cleaning  MoUuscan  Shell  with  Sodium  Hypochlorite  (Clorox) 4/ 

David  R.  Lindberg 

Variations  in  the  Limpet.  CoUiseUa  ochracea, 

and  the  Distribution  oiNatoacmea  testudinalis  (Acmaeidae) ^ 

HansBertsch                                                                                   t,             /i^    ^       r>    c   \  k^ 

Tropical  Faunal  AffinitiesofOpisthobranchsft-om  the  PanamicProvmce  (Eastern  Pacific) i>i 

Melissa  A.  Barbour 

A  Note  on  the  Distribution  and  Food  Preference  of  Cadlina  laems 

(Nudibranchia:  Chromodoridae) 

Dorothea  S.  Franzen  tt  •    jo    <.  kq 

Catinella  paralleled  A  New  Succinidae  (Pulmonata)  from  Midwestern  United  States ^^ 

Billy  G.  Isom,  Sally  D.  Dennis  and  Charles  Gooch 

Rediscovery  of  Some  Pleurocerids  (Gastropoda)  Near  Muscle  Shoals, 

Tennessee  River,  Alabama 

Amy  Shrader  Van  Devender 

A  New  Vertkjii  (Pulmonata:  Pupillidae)  from  the  Ozarkian  Uplift 

Alton  C.  Boozer  and  P.  E.  Mirkes 

Observations  on  the  Fingernail  C\&mjiusculium  partumeivm  (Pisidiidae), 

and  its  Association  with  the  Introduced  Asiatic  Clam,  Corbiculafluminea '-i 

Billy  G.  Isom,  Charles  Gooch  and  Sally  D.  Dennis 

Rediscovery  of  a  Presumed  Extinct  River  Mussel,  Dijf^nnmia  sulcata  (Unionidae) »4 

Terrence  M.  Gosliner  ,      j    j     ^  qr 

A  Review  of  the  Systematics  of  CylichneUa  Gabb  (Opisthobranchia:  Scaphandridae) "•'^ 

Robert  S.  Prezant  „„ 

Shell  Spinules  of  the  Bivalve,  L?/onsia  hyalina ^^ 

William  J.  Clench 

A  Biography  of  Andrew  Garrett,  Early  Naturalist  of  Polynesia:  Part  2: 

Catalogue  of  Molluscan  Species  and  Bibliography 

Hugh  J.  Michael-Tapping  ,      ,         ,  ino 

The  Caecidae  (Gastropoda:  Rissoacea)  of  Water  Island,  U.S.  Virgin  Islands,  with  a  new  species W6 

Donald  R.  Moore  and  Mabel  Fentress  Miller 

Discovery  of  Living  Bivalved  Gastropods  in  the  Florida  Keys i"" 


56,  92       Recent  Death  (Teramachi) 83 

Retiring  Business  Manager  of  The  Nautilus 

For  nearly  half  a  century  Mrs.  H.  Burrington 
Baker,  known  to  her  friends  as  Bunny,  has  either 
collected  shells,  written  about  shells,  or  has  been 
actively  assisting  scientists  and  editors  in  their 
malacological  endeavors.  S(K)n  after  she  married 
the  zoologist,  and  co-editor  of  The  Nautilus,  H. 
B.  Baker  in  1941,  Bunny  began  proofing  manu- 
scripts and  keeping  the  subscription  records. 
Throughout  the  following  38  yeai-s  her  voluntary 
assistance  has  made  the  continuation  of  Tlic 
NaiitUii.<;  possible. 

Mrs.  Baker  has  been  the  fourth  Business  and 
Subscription  Manager  in  the  93-year  life  of  this 
journal.  The  first  was  its  co-founder,  William  D. 
Averell  (1853-1928)  of  Mt.  Airy,  Philadelphia, 
who  served  for  the  first  three  volumes  from  1886 
to  1890.  The  second  was  Charles  W.  Johnson 
(1863-1932)  of  Philadelphia  and  later  of  Boston 
who  served  from  1890  until  his  death  in  1932  over 
a  period  of  42  volumes.  The  third  was  Horace 
Burrington  Baker  (1889-1971),  of  Havertowm,  Pa., 
who  served  from  1932  to  1958  when  he  then  be- 
came senior  editor.  It  was  at  this  time  during  the 
71st  volume  that  Bunny  became  the  fourth  Busi- 

ness Manager  and  has  served  in  that  capacity  for 
20  years.  Although  retiring  now,  and  still  very 
active  in  the  affairs  of  the  Delaware  County 
Memorial  Hospital,  Bunny  is  in  excellent  health 
and  will  continue  to  give  sage  advice  and  guid- 
ance to  The  Nautilus. 

Bernadine  Barker  Baker  was  bom  October  1, 
1906,  in  Quincy,  Massachusetts,  and  received  her 
A.  B.  degree  in  1928  from  Radcliffe  College  in 
Cambridge,  Mass.  She  taught  at  Burdett  College 
for  three  years,  then  was  Financial  Secretar>'  at 
the  Children's  Museum  in  Boston  where  she  first 
became  interested  in  shells.  With  her  co-worker 
Mildred  Seymour  (later  MacCoy),  Bunny  ventur- 
ed on  an  expedition  with  Harvard  scientists  in 
1934  to  the  Everglades  of  Florida. 

Mi-s.  Baker  is  a  Life  Member  of  the  American 
Malacological  Union,  having  joined  as  early  as 
1934,  and  served  as  its  Treasurer  from  1966  to 
1972.  She  was  Secretary  of  the  Boston  Mala- 
cological Club  from  1935  to  1941,  and  is  a  charter 
member  of  both  the  Philadelphia  and  Wilmington 
Shell  Clubs.  Her  interests  have  been  mainly  in 
marine  mollusks.  Her  collection  was  donated  to 
the  Museum  of  Comparative  Zoology,  at  Harvard, 
a  few  years  ago.  She  published  two  scientific  ar- 
ticles in  The  Nautilus,  one  in  1950  on  the  marine 
mollusks  of  St.  Petersburg,  and  the  other  in  1951 
on  "Interesting  Shells  from  the  Delmarva  Penin- 

Bunny  was  engaged  to  her  future  husband  at 
the  1941  A.  M.  U.  meetings  in  Rockland.  Maine, 
and  appropriately  they  spent  their  hone.vmoon  on 
shell-rich  Sanibel  Island,  Florida.  Until  "H.  B.'s" 
death  in  1971,  she  assisted  in  77!*  Nautilus  mat- 
ters, and  raised  two  daughters,  Elizabeth,  now 
Mrs.  Warren  Brandkamp,  and  Abigail,  now  Mrs. 
John  Kraljevich.  She  has  four  grandchildren.  Her 
husband  immortalized  her  name  in  malacological 
literature  in  1942  by  naming  a  new  genus  and 
new  species  of  Mexican  land  snail,  Bunnya  ber- 
nadinae.  For  17  years  Bunny  has  been  a  vol- 
unteer worker  at  the  Delaware  County  Memorial 
Hospital  (see  Our  Family,  vol.  5,  no.  10,  Aug. 
1977),  and  she  continues  to  assist  in  their  Gift 
Shop.  Among  her  hobbies  are  hooking  rugs  and 
collecting  miniature  bunnies.  Bunny  may  still  be 
reached  by  her  friends  at  11  Chelten  Road, 
Havertown,  PA,  19083.  (R.  T.  Abbott). 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      47 


Melbourne  R.  Carriker 

College  of  Marine  Studies 
University  of  Delaware 
Lewes,  Delaware  19958 


The  corrosive  effect  of  sodium  hypochlorite  (commercial  clorox)  on  the  ultra- 
structure  of  the  (i)yanir  components  of  the  shell  of  the  bivalve  Mytilus  edulis 
Linne  is  described,  and  the  detrimental  results  are  related  to  cleaning  of  mollus- 
can  shells  preparatory  to  storage  in  collections. 


Sodium  hypochlorite  solutions  have  been  em- 
ployed routinely  by  shell  collectors  for  some  time 
to  remove  algal  and  other  organic  grovrths  from 
the  exterior  of  molluscan  shells  in  preparation 
for  storing  them  in  collections  (Abbott,  1954; 
Bales,  1974). 

Commercial  clorox,  5.25%  sodium  hypochlorite, 
available  at  most  grocery  stores,  does  not 
disfigure  the  mineral  portions  of  shells,  but  does 
dissolve  the  organic  matter.  Soft  molluscan  and 
other  tissues  are  dissolved  rapidly  (in  a  few 
seconds),  while  tough  tissues,  like  molluscan 
periostracum  and  ligament,  take  considerably 
longer.  Hamilton  (1969),  for  example,  was  forced 
to  treat  valves  of  tellinid  bivalves  for  as  long  as 
30  to  60  days  to  completely  remove  the  perios- 
tracum. Differential  dissolution  of  organic  matrix 
of  shell  by  sodium  hypochlorite  has  been  used  to 
good  advantage  by  such  investigators  as  Towe 
and  Hamilton  (1968),  Mutvei  (1970),  and  Carriker 
(1978)  in  the  study  of  the  fine  structure  of  the 
units  of  molluscan  shell. 

The  purpose  of  this  note  is  to  describe  the  ef- 
fect of  clorox  on  molluscan  shell  at  ultrastruc- 
tural  magnifications,  and  to  discuss  these  obser- 
vations with  reference  to  the  procedures  em- 
ployed by  shell  collectors  in  cleaning  shells. 


Shells  of  the  bivalve  Mytilus  edulis  Linne  were 
employed  for  testing  the  effect  of  solutions  of 
sodium  hypochlorite.  Rapidly  growing  specimens, 
approximately  6  cm  in  length,  were  collected  in 

the  vicinity  of  Woods  Hole,  Massachusetts. 
Valves,  freshly  cleaned  of  meats  and  washed  in 
tap  water,  were  shattered  with  a  blow  from  a 
hammer.  Pieces  of  shell,  about  4  to  8  mm  in  long- 
est dimension,  were  selected  from  the  thick  mid- 
dle region  of  the  valves.  All  major  layers  of  shell 
were  represented  in  each  fragment:  the  exterior 
organic  periostracum,  the  calcific  prismatic 
stratum,  and  the  aragonitic  nacreous  layer  next 
to  the  mantle  (see  Carriker,  1978,  for  review  of 
the  ultrastructure  of  the  shell  of  this  bivalve). 

Several  pieces  of  shell  were  placed  in  each  of 
three  small  beakers,  each  beaker  containing  30  ml 
of  full  strength  commercial  clorox  (5.25%  sodium 
hypochlorite).  Beakers  were  covered,  gently  swirled 
by  hand  from  time  to  time,  and  maintained 
at  room  temperature  in  a  laboratory  normal- 
ly lighted  with  overhead  fluorescent  illumina- 
tion. Shell  pieces  in  beaker  a)  were  immersed  in 
clorox  for  10  minutes,  those  in  beaker  b)  for  30 
minutes,  and  those  in  beaker  c)  for  40  hours.  At 
the  end  of  these  periods,  shell  fragments  were 
rinsed  several  times  in  cold  tap  water,  drained  on 
absorbent  paper,  and  dried  in  a  stream  of  warm 
air.  Representative  pieces  from  the  three  beakers 
were  then  mounted  on  1  cm  brass  stubs  with 
silver  paint,  dried  in  an  oven  at  60°C  for  a  day, 
coated  with  gold  in  vacuum,  and  examined  with  a 
scanning  electron  microscope,  using  magnifica- 
tions of  2000  to  6000  times  at  a  voltage  of  15  k\'. 


Ridges  on  the  untreated  surface  of  the  perios- 
tracum of  Mytilus  edulis  ranged  in  width  from 


April  Z%  1979 

Vol.  93  (2-3) 

1.4  to  2  fiin  (Fig.  1).  This  corrugated  pattern  was 
completely  destroyed  by  treatment  with  clorox 
for  40  hours  (Fig.  2),  leaving  cracked,  buckled 
shreds  of  periostracum  draping  over  the  tops  of 
tubercles  of  the  thin  mo-saicostracal  layer  (Car- 
riker,  1979)  which  binds  the  periostracum  to  the 
prismatic  layer  of  the  shell.  Immersion  of  perios- 
tracum in  clorox  for  shorter  periods  resulted  in 
progressively  less  erosion  of  its  surface. 

Treatment  of  fractured  surfaces  of  the 
prismatic  layer  of  shell  with  clorox  for  40  hours 
(Fig.  5)  caused  complete  removal  of  the  inter- 
pristmatic  organic  matrix  (conchiolin)  which  sur- 
rounds each  individual  prism  as  an  envelope  and 
binds  adjacent  prisms  to  each  other  (compare 
with  Fig.  3;  prisms  roughly  1  to  3  fim  in  major 
cross   sectional   dimension).   The  treatment   also 

FIG.  1.  Exterior  of  periostracum  i/Mytilus  edulis  near  edge 
of  valve  illustrating  ntrrmal,  smonthly  corrugated,  untreated 
surface.  Scanning  electron  micrograph.  Scale  bar  =  2  \im. 
2,  Exterior  of  periostracum  after  treatment  with  clorox  for  JfO 
hours.  Periostracum  was  partially  dvisolved.  and  as  it  dried, 
cracked  atul  warped.  Scanning  electron  micrograph.  Scale  bar 
—  S  fim.  3,  Normal  untreated  fractured  surface  of  prismatic 
layer  of  shell  showing  broken  erids  and  .'ddes  of  indicidual. 
closely  fitting,  anvil-shaped  prisms.  Scanning  electron 
micrograph.  Scale  bar  =  2  yan.  4,  Fractured  surface  of 
prismatic  layer  of  shell  treated  with  clorox  for  10  minutes. 
Most  of  interprismatic  organic  envelope  uvs  removed  from 
each  pri.'sm  exposing  pattern  of  mineral  crystals  beneath. 
Scanning  electron  micrograph.  Scale  bar  =  2ym. 

etched  some  of  the  intraprismatic  organic  matrix 
from  the  mineral  crj'stals  within  the  prisms, 
revealing  the  jagged  edges  of  what  appeared  like 
mineral  platelets.  Treatment  with  clorox  for  10 
minutes  (Fig.  4)  resulted  in  the  removal  of  only 
part  of  the  interprismatic  organic  matrix. 

Exposure  of  the  mantle  surface  of  the  nacre  to 
clorox  for  40  hours  resulted  in  dissolution  of  the 
organic  matrix  which  surrounds  individual 
lamellae  and  cements  them  to  each  other  (Fig.  7, 
compare  with  Fig.  6;  lamellae  roughly  5  to  10  (jm 
in  longest  dimension).  Removal  of  the  matrix 
created  a  pattern  of  polygonal  figures  illustrated 
in  the  several  terraces  of  lamellae  exposed  in 
Figure  7.  A  threefold  enlargement  of  Figure  7 
(Fig.  8)  showed  further  that  the  clorox  also 
solubilized  some  of  the  intracrystalline  organic 
matrix  within  the  lamellae,  exposing  what  ap- 
peared like  internal  lath  shaped  substructures. 


As  other  workers  have  discovered  (Carriker, 
197S.  Hamilton.  1969;  Mutvei,  1970;  Towe  and 
Hamilton.  1968).  clorox  is  a  highly  efficient 
solubilizer  of  molluscan  organic  materials.  Ex- 
cessive use  of  full  strength  clorox  in  the  cleaning 
of  shells,  however,  can  alter  the  ultrastructural 
nature  of  the  shell  surface,  whereas  when  em- 
ployed with  discretion,  the  chemical  is  extremely 
useful  in  cleaning  periostracal  and  ligamental 
surfaces  of  molluscan  shells.  Unpublished  obser- 
vations and  the  published  work  of  others  (Abbott, 
1964:  Bales,  1974)  demonstrated  that  it  is  dif- 
ficult to  prescribe  a  given  concentration  or  time 
for  the  use  of  clorox  in  cleaning  the  exterior 
surface  of  a  particular  species  of  shell.  The  age  of 
the  shell  and  previous  exposure  of  the  surface  to 
weathering  and  to  microbiological  action  are  fac- 
tors which  increase  the  vulnerability  of  the  sur- 
face to  dissolution.  Each  specimen  must  thus  be 
treated  individually,  and  application  of  the 
chemical  must  be  made  initially  for  a  brief 
period  of  time.  For  fragile  specimens  it  is  impor- 
tant to  use  clorox  diluted  five  to  twenty  or  more 
times  with  tap  water.  S.  E.  Siddall  and  R.  A. 
Lutz  (personal  communication),  for  example,  em- 
ploy 2%  alkalized  (pH  9)  clorox  to  dissolve  the 
ligament  of  mussel  larvae  when  examining  the 

Vol.  93  (2-3) 

Api'il  23. 1979 

THE  NAUTILUS      49 

FIG.  5.  Fractured  surface  of  prismatic  layer  of  shell  treated 
with  clorox  for  iO  hours.  Interprismatic  and  some  of  in- 
traprismatic  organic  matrix  was  solvbilized,  leaving  con- 
spiawus  spaces  among  prism  ends.  Scanniitg  electron 
micrograph.  Scale  bar  =  2  yim.  6,  Normal,  untreated,  oblique, 
fractured  surface  of  nacreous  layer  of  shell  showing  teiraces 
of  brick-shaped  lamellae.  Scanning  electron  micrograph.  Scale 
bar  =  2  fim.  7,  Surface  of  nacreous  layer  of  shell  facing  man- 
tle treated  uith  clorox  for  iO  hours.  Organic  matrix  between 
adjacent  lamellae  was  dissolved  resulting  in  pattern  of 
polygonal  figures.  Scanning  electron  micrograph.  Scale  bar  = 
6  \m.  8,  Same  surface  as  in  Fig.  7  magnified  three  times 
more.  Dissolution  of  superficial  organic  matrix  within 
lamellae  revealed  substructure  of  lamellae.  Scanning  electron 
micrograph.  Scale  bar  =  iftm. 

hinge  structure.  After  initial  immersion  in 
clorox,  careful  rinsing  in  tap  water,  and  drying, 
the  surface  of  the  specimen  should  be  examined 
for  effectiveness  of  removal  of  organic  growths 
and  for  possible  loss  of  sheen  and  color  resulting 
from  chemical  deterioration  of  the  surface. 
Guided  by  frequent  visual  examinations  (prefer- 
ably under  a  binocular  microscope  especially  for 
small  fragile  specimens),  the  shell  preparator  can 
generally  safely  employ  the  required  number  of 
immersions  in  clorox  to  remove  extraneous  or- 
ganic materials  without  objectionably  altering 
the  surface  of  the  periostracum  and  ligament. 

The  organic  matrix  of  the  nacreous  inner  sur- 
face of  valves,  however,  is  much  more  vulnerable 
to  dissolution  by  clorox  than  periostracum  and 

ligament  (see  Fig.  7,  8).  With  the  exception  of 
fragments  of  flesh  clinging  to  the  muscle  scars 
(myostracum),  the  nacreous  surface  is  usually 
clean  in  freshly  opened  molluscs.  It  is  thus 
necessary  only  to  dissolve  the  organic  matter  on 
myostracal  areas.  This  can  be  done  without 
harming  the  nacre  to  any  extent  by  carefully 
"applying"  clorox  only  over  the  myostracal  sur- 
faces under  a  binocular  microscope,  observing  the 
same  precautions  given  in  the  previous  paragraph 
for  periostracal  and  ligamental  surfaces. 

Malacologists  and  conchologists  often  soak 
freshly  collected  shells  in  tap  or  seawater  for  a 
time  to  allow  removal  pf  muscle  tissue  from  the 
myostraca  by  autolysis  and  bacterial  decomposi- 
tion. This  treatment  is  effective  in  removing 
tissues,  but  caution  must  be  observed  as  the 
treatment  may  also  disfigure  the  nacreous  sur- 
face as  a  result  of  the  accumulation  of  acids  in 
the  water.  K  water  must  be  used,  it  is  safer  to 
employ  seawater  because  it  possesses  a  con- 
siderably greater  buffering  capacity  than  does 

The  observations  reported  in  this  paper  suggest 
that  caution  should  be  exercised  against  over  ex- 
posure to  clorox  in  cleaning  shells  especially  for 
permanent  storage  in  study  collections. 


Thanks  are  extended  to  Virginia  Peters  for  col- 
laboration in  the  scanning  electron  microscopy,  to 
W'alter  S.  Kay  for  preparing  the  final  prints  for 
publication  and  to  R.  Tucker  Abbott  for  helpful 
comments  on  the  manuscript.  University  of 
Delaware,  College  of  Marine  Studies  Contribution 
Number  123. 


Abbott,  R.  T.  1954.  American  Seashells.  D.  Van  Nostrand  Co., 

Inc..  Princeton.  N.  J.  .541  pp. 
Bales,  B.  R.  1974.  Cleaning  marine  shells,  in  M.  K.  Jacobson. 

Ed.,  How  to  study  and  collect  shells.  Amer.  Malacological 

Union,  pp.  12-16. 
Carriker.  M.  R.  1977.  Ultrastructural  evidence  that  gastropods 

swallow  shell  rasped  during  hole  boring.  Biological  Bulletin 

152:  325-336. 
.  1978.  Ultrastructural  analysis  of  dissolution  of 

shell  of  the  bivalve  Mytilus  edulis  by  the  accessory  boring 

organ  of  the  gastropod  Urosalpinx  cinera.  Marine  Biology 

48:  105-134. 

50      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

1979.  L'ltrastructure  of  the  mosaicostracal  layer  of 

the  shell  of  the  bivalve  Mylilus  edulis.  (Submitted  to  The 
Veliyer).  In  pres.s.  vol.  21.  no.  4. 

Hamilton,  G.  H.  1969.  The  taxonomic  significance  and 
theoretical  origin  of  surface  patterns  on  a  newly  discovered 
bivalve  shell  layer,  the  mosaicostracum.  The  Veliger  11: 

Mutvei,  H.  1970.  Ultrastructure  of  the  mineral  and  organic 
components  of  molluscan  nacreous  layers.  BiominTulizatum 
Res.  Rept.  2:  48-74. 

Tnwe,  K.  M..  G.  H.  Hamilton.  1968.  Ultrastructure  and  infer- 
red calcification  of  the  mature  and  developing  nacre  in 
bivalve  mollusks.C<i/r.  Tiss.  Res.  1:  306-318. 



David  R.  Lindberg 

Department  of  Invertebrate  Zoology 

California  Academy  of  Sciences 

San  Francisco,  California  94118  U.S.A. 

In  August,  1975,  I  collected  a  series  of  small 
limpets,  less  than  10  mm  in  length,  from  the 
shells  of  the  abalone,  Haliotis  mfeacens  Swainson, 
1822,  at  a  depth  of  8  m  off  Kruse  Ranch,  Men- 
docino County,  California  (38°35'N).  My  initial  ef- 
forts to  identify  the  specimens  using  shell 
characters  failed,  so  I  examined  radulae  from 
several  of  the  specimens.  Radulae  from  other 
small  limpets  which  had  been  obtained  from 
shells  of  Tegula  pulligo  (Gmelin,  1791),  collected 
in  Monterey  Bay,  California  (36°36'N),  had 
previously  been  prepared.  When  compared  to 
those  of  the  Kruse  Ranch  specimens,  the  radulae 
proved  to  be  very  similar,  although  the  shells  of 
the  two  groups  of  specimens  differed  markedly  in 
coloration  and  morphology-. 

As  additional  material  was  examined,  rudular 
characters  initially  thought  to  be  unique  to  these 
two  sets  of  specimens  were  also  found  to  be  pre- 
sent in  CoUviella  ochracea  (Ball,  1871).  I  now 
consider  the  limpets  from  H.  nifescens  and  T. 
pulligo  to  be  previously  unreported  forms  of  C. 

Subsequent  to  this,  I  encountered  problems  in 
attempting  to  establish  the  most  northern  dis- 
tributional record  for  C  ochracea.  Specimens 
identified  as  C.  ochracea  from  western   Alaska 

were  not  similar  to  southern  specimens.  After  ex- 
tensive examination  and  comparisons,  these  spec- 
imens were  recognized  as  Notdacmeo  testudinalis 
(Muller,  1776),  the  presence  of  which  in  the  east- 
ern Pacific  has  been  the  subject  of  controversy. 

This  paper  discusses  and  figures  the  various 
forms  of  C.  ochracea  and  contains  notes  on  the 
natural  history  of  this  species.  Also  included  is  a 
review  of  the  presence  of  N.  testudinalis  in  the 
eastern  Pacific,  with  a  discussion  of  its  similari- 
ties to,  and  differences  from,  C.  ochracea. 

Abbreviations  used  in  the  text : 

CAS  -  California  Academy  of  Sciences,  San 

Francisco,  California. 

CASG  -  Department  of  Geology,  Cal.  Acad. 


CASIZ  -  Department  of  Invertebrate  Zoology, 

Cal.  Acad.  Sciences. 

LACM    -    Los    Angeles    County    Museum    of 

Natural  History,  Los  Angeles,  California,  De- 
partment of  Malacology. 

Collisella  ochracea 

Collisella  ochracea  is  a  little-known  eastern 
Pacific  species.  Dall  (1871:  249)  described  it  from 
Monterey,  California,  as  a  variety  of  Acmaea 
patina  Rathke,  1833  [now  Notoacmea  scutum 
(Riithke,  1833)],  and  it  was  treated  as  such  by 

Vol.  93  (2-3) 

April  23. 1979 

THE  NAUTILUS      51 

Dall  (1879:  1914;  1921),  Pilsbry  (1891),  and 
Oldroyd  (1927).  A.  R.  Grant  (1933)  was  the  first 
worker  to  recognize  C.  ochracea  as  a  distinct 
species  and  in  a  later  thesis  (Grant,  1938)  correct- 
ly placed  Acmaea  peramabilis  Dall,  1872,  in 
synonymy.  Observations  by  Grant  (1938)  of  the 
radula  of  C.  (xhracea  further  demonstrated  its 
distinctness.  The  radular  strap  was  found  to  bear 
vestigial,  marginal  teeth  (uncini),  the  presence  of 
which  assigned  C.  ochracea  to  the  genus  Callisella 
rather  than  to  Notoacmea.  the  genus  to  which  A'. 
scutum  belongs.  Grant's  treatment  of  C.  ochracea 
was  followed  by  the  majority  of  subsequent 
workers,  including  Keen  (1937),  Burch  (1946), 
Smith  and  Gordon  (1948),  Light,  et  al.  (1955), 
Fritchman  (1961),  McLean  (1966,  1969).  and 
Carlton  and  Roth  (1975).  However,  as  recently  as 
1974,  C.  ochracea  has  again  been  erroneously 
listed  as  a  variety  of  A^.  scutum  (Abbott,  1974: 

In  1945  and  1946  Avery  Ransome  (Grant)  Test 
published  parts  of  her  1933  and  1938  theses.  In 
the  first  paper  the  ecology  of  C.  ochracea  was 
discussed  in  a  single  paragraph  in  which  she 
stated  that  the  limpet  occurs  in  the  lower  inter- 
tidal  zone  on  rocks  that  are  largely  bare  of 
macroscopic  algae,  appearing  to  be  limited  to  this 
habitat  by  food  (microscopic  algae),  the  lack  of 
competition,  and  permanent  submergence.  In  the 
later  paper  (Test,  1946),  C.  ochracea  was  reported 
to  be  related  to  Collisella  pelta  (Rathke,  1833) 
based  on  a  study  of  the  radular  characters.  My 
own  observations  do  not  support  this  relationship 
nor  is  another  evident  at  this  time.  Yonge  (1962) 
included  the  species  in  his  study  of  mantle  cavity 
currents  in  acmaeids.  McLean  (1969:  17)  reported 
that  C.  ochracea  is  one  of  the  few  acmaeid  species 
occurring  subtidally.  McLean  (loc.  cit.)  was  also 
the  first  worker  to  refer  to  C.  ochracea  as  being  a 
common  species.  The  range  of  C.  ochracea  is  Cap- 
tain's Bay,  Unalaska  Island.  Alaska  (53°03'N)  to 
Isla  Cedros.  Baja  California,  Mexico  (28°12'N). 

The  Forms  of  Collisella  ochracea 
Collisella  ochracea  is  an  eurytopic,  polyt>-pic 
species.  It  occurs  on  several  different  substrata 
and  has  shell  color  patterns  and  morphology  that 

vary  with  the  substratum  occupied.  One  form  oc- 
curs on  the  shells  of  trochid  gastropods.  A  second 
variation  occurs  on  encrusting  coralline  algae  and 
two  other  forms  occur  in  the  low  int«rtidal  and 
subtidal  zones.  Only  these  last  two  were  recog- 
nized and  described  by  Grant  (1933:  111). 

Although  each  form  is  described  separately  be- 
low, several  general  characters  are  present  on  all 
specimens.  The  sculpture  of  C.  ochracea  consists 
of  fine,  non-bifurcating  riblets.  The  riblets  are 
consistently  straight  and  evenly  spaced.  The  aper- 
ture of  C.  ochracea  may  vary  from  circular  (Fig. 
2)  to  elongate  (Fig.  4). 

Solid  and  Tessellate  Forms  (Figs.  1-2) 

Description:  Shell  of  low  to  medium  profile; 
apex  in  anterior  third  of  shell  length.  Anterior 
and  lateral  slopes  straight,  posterior  slope  slight- 
ly convex.  Solid  form  pale  yellow  to  rose  red. 
Tessellate  form  brown  to  gray,  with  symmetrical 
white  markings,  pattern  finer  at  apex  than  at 
edge.  White  markings  sometimes  drawn  out  into 
bars  at  edge.  Internal  margin  darker  than  in- 
termediate or  apical  areas,  sometimes  streaked 
with  white  corresponding  to  external  pattern.  In- 
termediate and  apical  areas  may  be  suffused  with 
blue.  Internal  stain,  when  present  in  solid  form, 
not  covering  apical  area. 

Remarks:  As  previously  stated  these  two  forms 
have  been  recognized  since  1933  and  they  occur 
on  smooth,  bare  rocks  and  reefs  in  the  low 
intertidal  and  subtidal  areas.  McLean  (1966: 
77)  stated  that  specimens  are  common  to  depths 
of  9  m,  but  are  seldom  collected  below  this. 

Coralline  Form  (Fig.  3) 

Description:  Shell  of  low  to  medium  profile: 
apex  in  anterior  third  of  shell  length.  Anterior 
slope  concave;  posterior  slope  convex;  lateral 
slopes  straight.  Aperture  anteriorly  narrowed. 
External  color  pattern  of  brown  to  red  coalescing 
markings  on  a  white  background;  pattern  at  apex 
finer  than  at  edge.  Apex  erodes  to  white.  Internal 
margin  white,  with  markings  corresponding  to 
pattern  at  external  edge;  internal  stain,  when 
present,  not  extending  into  apical  area.  Shell 

52      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

Remarks:  This  form  occurs  on  intertidal  and 
subtidal  substrata  encrusted  with  coralline  algae 
of  the  genus  Lithothamnion.  including  rocks, 
boulders,  and  the  shells  of  H.  rufescens.  The  con- 
cave anterior  slope  of  this  form  distinguishes  it 
from  the  other  forms  of  this  species.  A  form  of 
Collisella  pelta  is  also  found  on  such  surfaces,  but 
it  is  readily  distinguished  from  C.  uchracea  by  its 
lack  of  fine  riblets. 

Epizoic  Form  (Fig.  4) 

Descriptidn:  Shell  of  medium  profile;  apex  in 
anterior  quarter  of  shell  length.  Anterior  and 
lateral  slopes  straight;  posterior  slope  slightly 
convex.  Aperture  elongate;  lateral  edges  parallel. 
External  color  tan  to  reddish  brown,  generally 
mottled  with  white  or  with  white  markings.  Solid 
forms  occur.  Apex  erodes  to  white.  Internal 
margin  dark,  with  or  without  white  markings 
corresponding  to  the  external  pattern  which  is 
visible  through  shell.  Generally  lacking  internal 

Remarks:  This  form  occurs  on  the  trochid 
gastropods  Tegula  brunnea  (Philippi,  1848), 
Tegula  montereyi  (Kiener,  1850),  and  Tegula 
pidligo  (Gmelin,  1791).  The  majority  of  my 
specimens  have  been  collected  from  T.  pulligo  in 
the  Monterey  Bay  area.  This  form  of  C.  ochracea 
has  been  found  on  T.  brunnea  and  T.  montereyi 
in  San  Mateo  County,  California,  and  a  single 
specimen  of  it  was  found  at  Bodega  Bay,  Marin 
County,  California,  on  T.  brunnea.  Trochid 
gastropods  are  commonly  utilized  as  substrata  by 
acmaeid  limpets.  Cnllisella  asmi  (Middendorff, 
1847)  was  considered  to  be  the  only  epizoic  limpet 

on  Tegula  funebralis  (A.  Adams,  1855).  However, 
McLean  (1966:  80)  reported  that  Collisella 
strigatella  (Carpenter,  1846)  was  also  abundant 
on  T  funebralis  in  the  Monterey  area,  and 
Brewer  (1975)  reported  six  additional  species  of 
acmaeid  limpets  on  T.  funebralis.  T.  funebralis  is 
a  mid-intertidal  species,  and  the  limpets  which 
occur  on  it  are  also  found  in  the  same  intertidal 
zone.  All  three  species  of  Tegula  on  which  C. 
ochracea  has  been  found  are  low  intertidal  and 
offshore  kelp  bed  species  (Carlton  and  Roth,  1975: 
502-503)  which  corresponds  to  the  habitat  of  C. 

Laminaria  Form 

After  the  manuscript  was  submitted  to  the  edi- 
tor a  fifth  form  of  Collisella  ochracea  was  brought 
to  my  attention  by  M.  G.  Kellogg,  Moss  Landing 
Marine  Laboratories,  Moss  Landing,  CA.  This  ad- 
ditional form  occurs  on  the  stipes  of  the  brown 
algae  Laminaria  dentigera  and  Pterygophora 
califomica;  both  algae  are  typical  habitats  of  Col- 
lisella instabilis  (Gould,  1846).  Both  C.  instabilis 
and  the  C.  ochracea  form  have  similar  gross  shell 
morphologies  (i.e.  elevated  anterior  and  posterior 
shell  margins),  but  differ  in  shell  markings  and 
sculpture.  The  C.  ochracea  form  is  brown  with 
white  markings  similar  to  those  of  the  tessellated 
form  described  above.  Collisella  instabilis  is  also 
brown  but  lacks  the  white  markings  although  the 
apical  area  typically  erodes  to  white.  The 
sculpture  of  the  C.  ochracea  form  is  as  described 
above,  with  straight,  raised  riblets.  The  sculpture 
of  C.  in.'^tabilis  consists  of  broadly-spaced  grooves 
giving  the  appearance  of  obscure,  flat  ribs. 

Figures  1-10  (see  opposite  page) 

All  figure.^  actual  xue  unless  otherwise  noted. 

FIGS.  1-10.  1-4.  Collisella  ochracea  (Dull).  1,  Tes-sellate  form.  California:  San  Mateo  County:  Pillar  Point.  CASIZ  No. 
0031,19.  2,  Solid  fiinn.  California:  Mendocino  County:  Little  River,  .5871?  CASCi  Type  Collection:  3,  Coralline  form.  California:  San 
Mateo  County.  Ano  Nucvo  Pirint.  CASIZ  No.  0OS:i96.  X  2.  4,  Epizoic  form.  California:  Monterey  C(mnty.  San  .Jme  Creek  Beach,  on 
Tegula  pulligo  (Gmelin).  CASIZ  No.  00.1:190.  X  2  5-6.  Raduia  i;/' Collisella  ochracea  (Datl).  California:  Mendocino  County:  Kruse 
Ranch,  CASIZ  No.  00;lil8,  X  250.  5,  Radular  tooth  ronfiyuration,  FLT  =  fiist  lateral  tooth:  SLT  =  .'<econd  lateral  tooth:  TI.T  = 
third  lateral  tooth,  U  =  uncinus.  6,  Brts-a/  plalc  ntoriiholoyy:  FLP  =  first  lateml  plate:  SLP  =  second  lateral  plate:  TI.P  —  third 
lateral  plate:  VP  =  ventral  plate:  AP  =  anterior  pivcess:  AS  —  anterior  .future.  7.  Collisella  ochracea  (Dall).  California:  Santa 
Cruz  Cmtnty:  Soqnet  Point,  CASIZ  No.  00:1:19:1.  Note  shell  color  pattern  change  at  apex.  Enlargement  X  7.  &.  Notoacmea 
testudinalis  (M'dler).  8A,  Ataxka:  Prittilof  Islandi.  St.  Paid  Island.  .58716  CAS(!  Type  Collection:  8B,  Alaska:  Kenai  Peninsula: 
Kachcmak  Hay.  Cohen  Island.  lACM  No.  7.1-20.  9-10.  Raduia  u/Notoacmea  testudinalis  (M'dler).  Alaska:  Prihilof  Island.^.  St.  Paul 
Island.  St.  Paul  Village.  LACM  No.  7:1-21,.  X.  200.  9,  Radular  tooth  configuration  (see  Fig.  H  for  legend).  10,  Basal  plate  niorphology 
(see  Fig.  Hfor  legend). 

Vol.  93  (2-3) 

April  23, 1979 

thp:  nautilus    as 









For  explanations,  see  opposite  page  (Lindberg  on  Acmaeidae). 

54    thp:  nautilus 

April  23. 1979 

Vol.  93  (2-3) 

The  Radula  of  Collisella  ochracea 

Although  shell  color  varies  significantly  in  this 
species,  radular  characters  appear  consistent. 

Grant  (1938:  pit.  30,  Fig.  2)  figured  the  radular 
strap  and  basal  plates  of  C.  ochracea,  but  did  not 
discuss  or  figure  tooth  configuration  or  mor- 
phologj'.  She  did  mention  the  presence  of  elon- 
gated uncini.  McLean  (1966:  77)  described  the 
lateral  teeth  and  basal  plate  morphologj',  and 
gave  length/width  ratios  for  the  ribbon  seg- 

The  radular  tooth  configuration  of  C.  ochncea 
(Fig.  5)  is  typical  of  members  of  the  genus.  The 
first  lateral  teeth  are  close  together  on  the  an- 
terior end  of  the  segment  and  are  rounded  distal- 
ly.  The  second  laterals  are  posterior  to  the  first 
laterals  and  are  sub-rectangular,  with  broad 
straight  cutting  edges.  The  third  laterals  are  obli- 
que and  are  distal  to  the  second  laterals;  they  are 
wedge-shaped  and  smaller  than  the  other  laterals. 
The  uncini  are  elongate  and  curve  over  the 
posterior  comers  of  the  ventral  plates.  The  tips 
may  be  slightly  broadened. 

The  basal  plate  morphology  of  the  radula  (Fig. 
6)  is  also  typical  of  members  of  the  genus.  The 
first  lateral  plates  are  sub-rectangular;  the  second 
lateral  plates  broad  and  posteriorly  rounded;  and 
the  third  lateral  plates  are  separated  from  the  sec- 
ond lateral  plates  by  a  strong  partial  suture. 
The  third  lateral  plate  is  biformed,  the  inner  sec- 
tion rounded  distally  and  extends  beyond  the  sec- 
ond lateral  plate  edge.  The  outer  section  is 
pointed  distally  and  extends  to  the  vicinity  of  the 
uncini.  The  ventral  plates  are  clearly  defined  and 
bear  both  a  strong  anterior  suture  and  pro- 
cess-the  anterior  process  is  difficult  to  see  in 
radular  mounts  with  closely  spaced  segments. 

Natural  History  Notes 

Specimens  of  C.  ochracea  of  both  sexes,  some 
with  shell  lengths  of  less  than  5  mm,  have  been 
found  in  a  gravid  state,  and  some  of  these  from 
central  California  are  known  to  have  been  col- 
lected in  the  months  of  February  through 

The  bathymetric  range  of  C.  ochracea  extends 
from  the  low  intertidal  (=   0.0  feet)  to  a  little 

over  40  m.  No  .submergence  in  the  southern  por- 
tion of  the  distribution  of  this  species  appears  to 
occur,  although  Baja  California  specimens  appear 
limited  to  areas  of  cold-water  upwellings. 

C  ochracea  also  occurs  in  the  turbid  water  of 
San  Francisco  Bay,  California  (37°48'N)  on  the 
sides  and  bottoms  of  small  rocks  embedded  in 
sand  and  gravel  sediments  and  on  fouled  pilings 
in  Monterey  Harbor.  The  occurence  of  C.  ochracea 
in  such  habitats  is  not  surprising  in  view  of 
Yonge's  (1962)  report  that  C.  ochracea  has  a  man- 
tle current  pattern  similar  to  that  of  Notoacmea 
test7idinali%  a  species  often  found  associated  with 
sediment-laden  water. 


While  the  epizoic  and  coralline  forms  of  C. 
ochracea  are  directly  referable  to  particular 
substrata,  the  solid  and  tessellate  forms  appear  to 
occur  homogeneously  in  the  intertidal  and  sub- 
tidal  areas  of  central  California.  However,  in  a 
survey  of  over  400  specimens  some  geographic 
correlations  of  these  forms  were  noted.  Tesselate 
forms  predominate  in  the  southern  part  of  the 
geographic  distribution  (south  of  38°N)  and 
decrease  to  the  north;  the  solid  forms  predomi- 
nate in  the  north  and  appear  to  decrease  to  the 
south  (Table  1). 

Some  movement  of  individuals  between  sub- 
strata may  exist.  These  movements  are  suggested 
by  changes  in  shell  morphology  and  shell  color. 
Solid  forms  have  been  examined  with  the  fine 
reticulate  pattern  of  the  coralline  form  visible  at 
the  apex  (Fig.  7).  The  presence  of  the  fine 
reticulate  pattern  may  indicate  movement  from  a 
coralline  substratum  to  the  exposed  rock  reefs, 
the  typical  habitat  of  solid  forms.  Changes  in 
shell  morphology  and  color  have  also  been  noted 
for  C.  pelta  which  may  change  substrata 
(McLean,  1966:  59). 

Notoacmea  testudinalis  (Muller) 

Although  well-known  on  the  east  coast  of 
North  America  (Abbott,  1974;  Emerson  and 
Jacobson,  1976),  Arctic  Canada  and  Europe  (Mac- 
pherson,  1971),  the  presence  of  Notoacmea 
testudinalis  in  the  northeastern  Pacific  has  been 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      55 

TABLE  1.  Getiymphiciil  Distribution  of  Solid  and  Teaselate  Firrms  o/Collisella  ochracea  iDdlj  in  the  Ka-steni  Piwijic. 


#  of  specimens   %  of  specimens 


#  of  specimens   %  of  specimens  SPECIMENS 





















































the  subject  of  considerable  debate.  Dall  (1871) 
considered  N.  testudinalis  to  be  readily  discern- 
able  from  Acmaea  patina  [=  Notoacmea  scutum] 
and  to  occupy  a  different  habitat.  In  1879,  Dall 
reversed  his  position  and  r^arded  the  two  as 
varieties  of  a  single  species.  Grant  (1938)  also 
considered  the  two  to  be  of  subspecific  rank  and 
to  intergrade  in  the  Alaskan  Arctic.  McLean 
(1%6),  Abbott  (1974),  and  Emerson  and  Jacobson 
(1976)  consider  A^.  testudinalis  to  be  limited  to 
Atlantic  and  Canadian  Arctic  waters  with  a  cog- 
nate, A^.  scutum,  in  the  eastern  Pacific.  Moskalev 
(1964)  considered  A^.  testudinalis  to  be  present  in 
Arctic  waters  and  to  extend  down  the  east  coast 
of  Asia. 

After  examining  shells  and  radulae  of  speci- 
mens from  Alaska  and  comparing  these  to  Cana- 
dian Arctic,  eastern  Atlantic,  and  European  spec- 
imens of  N.  testudinalis.  I  have  concluded  that  N. 
testudinalis  occurs  in  the  northeast  Pacific  and 
that  Ball's  first  account  (1871)  was  correct  as  to 
the  species  habitat  and  distribution.  Based  on 
materials  in  the  collections  of  the  Los  Angeles 
County  Museum  and  the  California  Academy  of 
Sciences,  the  west  American  distribution  of  this 
species  in  Alaska  is  from  Point  Barrow  (7r22'N) 
(CASG  #35056)  to  Goose  Island,  Icy  Strait 
(58°13'N)  (CASG  #48915)  and  eastward  to  the 
Pnbilof  Islands  (.57°08'N,  170°15'W)  (CASG 
#21975).  In  the  eastern  Pacific  its  habitat  appears 
to  be  subtidal,  although  it  occurs  intertidally  in 
the  eastern  Atlantic  and  Europe.  Its  subtidal 
habitat  may  contribute  to  its  success  in  northern 
waters,  as  it  occurs  below  the  level  of  sea  ice  and 

low  winter  air  temperatures.  It  has  also  been  sug- 
gested that  this  species  may  migrate  into  the  sub- 
tidal during  the  winter  to  avoid  adverse  condi- 
tions (Willcox,  1905:  327).  In  comparison,  A^. 
scutum  is  an  intertidal  species,  not  knovm  to 
migrate  and  its  northern  distribution  may  be 
limited  by  sea  ice  and  adverse  winter  weather. 
Therefore,  in  those  areas  where  these  two  species' 
geographical  distributions  overlap  (the  Aleutians 
to  Icy  Strait,  Alaska),  A^.  scutum  and  A',  testudi- 
nalis appear  to  be  segregated  by  habitat. 

The  occurence  of  A^.  testudinalis  in  the  eastern 
Pacific  is  similar  to  the  distribution  of  Coliisella 
alveus  (Conrad.  1831)  which  occurs  in  both  the 
North  Pacific  and  the  North  Atlantic. 

Arguments  against  the  presence  of  both  A'. 
scutum  and  A^.  testudinalis  as  separate  species  in 
the  eastern  Pacific  (Dall,  1879;  Test,  1938)  have 
been  based  on  the  presence  of  supposed  in- 
tergrades  (hybrids)  in  the  Arctic.  While  the 
similarities  of  shell  micro-structure  and  radular 
morphology  suggest  that  speciation  has  been  re- 
cent, I  consider  A^.  testudinalis  and  N.  scutum 
sufficiently  dissimilar  to  be  considered  specific. 

Comparison  of 
Notoacmea  testudinalis  and  Coliisella  ochracea 

Although  the  tessellate  form  of  C.  ochracea  ap- 
pears to  be  uncommon  in  the  higher  latitudes,  it 
can  be  confused  with  N.  testudinalis  (cf.  Figs.  1 
and  8b).  Both  species  have  similar  gross  color  pat- 
terns (Fig.  8),  and  in  both,  external  sculpture  con- 
sists of  numerous,  fine,  non -bifurcating  riblets. 

56      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

As  in  most  forms  of  C.  ochracea,  the  internal 
stain  of  N.  testudinalis  does  not  cover  the  apex, 
and  the  external  apex  of  both  is  white.  However, 
the  shell  of  A^.  testudinaiia  is  larger  and  heavier 
than  that  of  C.  ochracea,  and  the  internal  stain  is 
sharp  and  distinct;  in  C.  ochracea,  the  stain  is 
typically  obscure  or  lacking. 

As  suggested  by  their  generic  allocations,  C. 
ochracea  and  A^.  testvAinalis  differ  in  radular 
structure  (Figs.  9-10).  The  radula  of  C.  ochracea 
bears  uncini;  N.  testudinalis  lacks  them.  In  N. 
testudinalui  the  first  and  second  lateral  teeth  are 
elongate  and  pointed  distally,  rather  than  short 
and  blunt  as  in  C.  ochracea.  The  basal  plates  of 
N.  testudinalis  differ  from  those  of  C.  ochracea  in 
that  the  third  lateral  plates  are  distinct  and  are 
located  laterally  from  the  second  lateral  plates. 
They  are  also  lobate  rather  than  bi formed  as  in 
C.  ochracea.  The  ventral  plates  of  both  species 
bear  anterior  processes. 


I  wish  to  acknowledge  Eugene  V.  Coan,  LACM 
and  CASG;  James  H.  McLean,  LACM;  and  EJarry 
Roth,  CASG,  for  their  criticism  of  this  paper.  Dr. 
McLean  also  loaned  numerous  specimens.  My 
special  thanks  to  Maurice  Giles,  CAS,  who 
photographed  and  reduced  the  figures.  This  work 
was  supported,  in  part,  by  SEA  GRANT  R/CZ-28. 


Abbott,  R.  T..  1974.  American  Seashells.  2nd  ed.:  1-663.  Van 

Nostrand  Reinhold,  N.  Y. 
Brewer,  B.  A.,  197.5.  Epizoic  limpets  on  the  black  turban  snail, 

Tegulafunebralis  (A.  Adams,  1855)  The  Veliger  17:  .307-310. 
Burch,  J.  Q..  1946.  Minutes,  Cmwh.  Ouh  of  So.  Calif.  57:  1-40. 
Carlton.  J.  T.  and  B.  Roth.  1975  Phylum  Mollusca:  shelled 

gastropods.  In:  R.  I.  Smith  and  J.  T.  Carlton  (eds.).  Light's 

Manual:  Intertidal  Invertebrates  of  the  Central  California 

Coast:  467.514.  Univ. Calif. 
Dall,  W.  H.,  1871.  Descriptions  of  sixty  new  forms  of  moliusks 

from   the  west  coast  of  America   and   the  north   Pacific 

Ocean,  with  notes  on  others  already  described.  AmFi:  Jour. 

0.»W(.  7:  9.3-160. 

1879.   Report   on    the   limpets   and   chitons   of 

Alaskan  and  Arctic  regions,  with  descriptions  of  genera  and 
species  believed  to  be  new.  Pmc.  U.S.  Nat.  Miis.  1:  281-.344. 

.  1914.  Notes  on  some  northwest  coast  Acmaeas. 

neNautihwsTS:  13-1.5. 

1921.    Summary    of   the    marine    shellbearing 

moliusks  of  the  northwest  coast  of  America  .  .  .  Bull.  i'S 

Nat.  Mtis.  112:  1-217. 
Emerson,  W.  K.  and  M.  K.  Jacobson.  1976.  The  American 

Mtiseum  of  Natural  History  Guide  to  Shells  .  .  .:  i-xviii. 

1-482.  Adfred  A.  Knopf 
Fritchman,  H.  K.  II.  1961.  A  study  of  the  reproductive  cycle 

in  the  California  Acmaeidae  (Gastropoda).  The  Vetiger  3: 

Grant.  A.  R..  1933.  A  revision  of  the  California  limpets  of  the 

genus  Acniaea  Ek;hscholtz.  Masters  of  Arts  Thesis.  Dept.  of 

Zool.,  Univ.  Calif.,  Berkeley:  1-142. 
19.38.  A  systematic  revision  of  the  genus  Aemaea 

Eschscholtz,  including  consideration  of  ecology  and  specia- 

tion.  Ph.  D.  Thesis.  Dept.  Zool..  Univ.  Calif.  Berkeley:  l-4;fi. 
Keen.  A.  M..  1937.  An  abridged  check  list  and  bibliography  of 

west    North    American    marine    Mollusca:    1-87.   Stanford 

Light,  S.  F..  et.  at..  19,54.  Intertidal  Invertebrates  of  the  Cot- 

tral  California  Coast:  1-446.  Univ.  Calif. 
Macpherson.  E..  1971.  The  Marine  Molluscs  of  Arctic  Canada. 

Nat.  Mm.  Nat.  Sci..  Pubt.  Oceanogr.  3:  1-149. 
McLean.  .1.  H..  1966.  West  American  prosobranch  Gastropoda: 

superfamilies    Patellacea.   Pleurotomariacea   and   Fissurel- 

lacea.  Ph.  D.  Thesis.  Dept.  Zool..  Stanford  Univ.:  1-262. 
1969.  Marine  shells  of  southern  California.  Los 

Angeles  County Mus.  Nat.  Hist.  Sci.  Ser.  24,  Zool.  11:  1-104. 
Moskalev,  L.  I..  1964.  Distribution  of  Acmaeidae  (Gastropoda, 

Prosobranchia)  in  the  North   Pacific.  Doklady.  Akademii 

Nauk.  SSSR  158:  1221-1222.  [in  Russian] 
Oldroyd,  I.  A..  1927.  The  Marine  Shells  of  the  West  Coast  of 

North  America  2:  1-340.  Stanford  Univ.  Pub.,  Univ.  Ser., 

Pilsbry.  H.  A..  1891.  Acmaeidae.  Manual  of  Conch.  13:  1-18.5. 

Smith,  A.  G.  and  M.  Gordon,  1948.  The  marine  moliusks  and 

brachiopods  of  Monterey  Bay.  California  and  vicinity.  Proc. 

Calif  Acad.  Sci.  26:  147-245. 
Test.   A.    R.    (Grant).    1945.    Ecolog>'   of  California   Acniaea. 

Ecology  26:  395-405. 
1946.  Speciation  in  limpets  of  the  genus  Acmaea. 

Univ.  Michigan.  Contrib.  Lab.  Vert.  Biol.  31:  1-24. 
Willoox,  M.  A..  1905.  Biology  of  Acmaea  testudinalis  Muller. 

Amer.  Nat.  39:  325-a33. 
Yonge,  C.  M..  1962.  Ciliary  currents  in  the  mantle  cavity  of 

species  of /lanwa.  The  Veligeri:  119-123. 

Hans  Bertsch  h;us  been  appointed  Curator  of  EJerkeley.  He  has  published  over  30  papers  on 
the  Department  of  Marine  Invertebrates  at  the  opisthobranchs,  and  has  had  extensive  field  ex- 
San  Diego  Natural  History  Museum  (P.  0.  Box  perience  in  Panama,  Baja  California,  Hawaii  and 
1390.  San  Diego,  CA  92112).  Dr.  Bertsch  was  bom  California.  Dr.  Bertsch  was  previously  Assistant 
in  1944  in  St.  I^ouis,  Missouri,  received  his  Ph.  D.  Professor  in  biology  at  the  Chaminade  University 
in     1976    from    the    University    of    California,  of  Honolulu. 

Vol.  93  (2-3) 

April  23. 1979 

THE  NAUTILUS      57 


Hans  Bertsch 

Department  of  Marine  Invertebrates 

Natural  History  Museum,  Balboa  Park 

P.O.  Box  1390,  San  Diego,  CA  92112 

This  is   a  preliminary  analysis   of  the   distribution   patteitis   of  species   of 
opisthobmnchs  (Gastropoda)   in   the   eastern   Pacific   that  are   kimum    to   occur 
elsewhere  in  the  tropics. 

The  opisthobranch  fauna  of  the  Panamic  pro- 
vince (tropical  West  America)  shares  the  greatest 
number  of  common  species  with  the  Califomian 
temperate  province  (Bertsch,  1973a).  Since  1970. 
various  zoogeographic  analyses  of  opisthobranch 
faunas  from  other  marine  provinces  have  been 
published  (e.g.,  Franz,  1970,  1975;  Thompson, 

Marcus  (1977)  enumerated  the  western  Atlantic 
opisthobranchs,  noting  which  species  occur  in 
other  marine  provinces.  She  lists  species  common 
to  the  Caribbean  and  tropical  west  American  pro- 
vinces and  some  amphi-Atlantic  tropical  forms. 
This  extremely  useful  tabulation  should  be  used 
with  some  reservation  because  certain  species 
listed  as  "circumtropical"  have  not  yet  been 
reported  from  the  Pacific  coast  of  America  (and 
hence  are  not  universally  circumtropical),  and 
sources  of  the  distributional  data  are  at  times 

Emerson  (1978)  has  compiled  a  list  of  the  pro- 
sobranch  gastropods  and  bivalves  which  are  com- 
mon to  the  Indo-Pacific  and  the  eastern  Pacific. 
This  preliminary  note  is  to  compliment  his  study, 
so  that  a  direct  comparison  can  be  made  between 
the  opisthobranchs  and  the  prosobranchs.  It  is 
also  intended  to  encourage  further  exchange  of 
information  on  Panamic  opisthobranchs.  Only 
several  tentative  generalizations  are  presented 
because  there  is  still  much  to  be  learned  about 
the  Panamic  opisthobranch  fauna. 


Table  1  summarizes  the  distribution  patterns 
of  species  of  opisthobranchs  in  the  eastern  Pacific 

that  are  known  to  occur  elsewhere  in  the  tropics. 
North-south  range  distributions  (i.e.,  affinities 
with  the  temperate  Califomian  and  Peruvian 
provinces)  are  generally  not  included.  Also  omit- 
ted are  the  pelagic  Thecosomata,  a  group  with 
several  circumtropical  species. 

Emerson  (1978)  and  most  of  the  writers  he 
cites,  have  divided  the  Panamic  province  into  2 
main  portions:  the  offshore  islands  (Guadalupe, 
Revillagigedo,  Clipperton,  Cocos,  and  the 
Galapagos)  and  the  continental  shelf  of  west 
America  (Gulf  of  California,  Mexican  and  Central 
American  coastline,  and  the  Islas  Tres  Marias). 
The  majority  of  Indo-Pacific  prosobranch  species 
occur  in  the  eastern  Pacific  only  on  the  offshore 
islands.  By  contrast,  all  of  the  opisthobranch 
species  known  from  the  eastern  Pacific  and  any 
other  tropical  province  occur  on  the  mainland 
coast.  Six  species  occur  also  at  the  Galapagos 

TABLE  1.  Extra-provincial  distributions  of  opisthobranch 
species  ocairrijig  in  the  eastern  Pacific.  Numbers  are  species 
with  that  distributional  pattern. 


















Circum  - 





















G:  One  of  the  species  (or  the  one  species  enumerated)  oc- 
curs in  the  Galapagos  Islands,  in  addition  to  being  present 
on  the  mainland  shelf  of  west  America 
P:  All  four  species  are  pelagic 

58      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

Islands.  No  inter-provincial  tropical  species  is 
presently  known  to  occur  only  on  the  offshore 
islands.  Of  course,  published  records  of 
opisthobranchs  from  these  offshore  sites  are  e.x- 
ceedingly  scarce.  Nevertheless,  the  occurrence  of 
ail  these  inter-provincial  tropical  species  on  the 
continental  shelf  is  a  very  different  pattern  than 
that  known  for  the  prosobranchs. 

So  far  as  is  known,  there  are  no  strictly 
Panamic  forms  which  also  occur  in  the  Indo- 
Pacific  province.  Excluding  the  circumtropicals, 
species  in  common  between  these  two  provinces 
are  apparently  Indo-Pacific  in  origin. 

The  inter-provincial  prosobranchs  are  primari- 
ly Indo-Pacific  (48  species),  with  a  very  small 
number  of  circumtropical  (tropicopolitan  is 
Emerson's  equivalent  term)  species  (7).  By  con- 
trast, there  are  11  circumtropical  and  4  Indo- 
Pacific  species  of  opisthobranchs  in  the  Panamic 

Evolutionary  relationships  with  species  in 
other  provinces  (including  generic-level  affinities) 
have  not  been  examined  among  the  opistho- 
branchs. Although  sister-species  are  well 
documented  among  prosobranch  gastropods  (Rad- 
win,  1969),  they  have  not  been  reported  for  the 
opisthobranchs.  Such  studies  would  yield  vital  in- 
formation on  the  origins  of  the  Panamic  opis- 
thobranch  fauna,  and  would  make  substantial 
contributions  to  our  knowledge  of  opisthobranch 
phylogeny  and  speciation  and  to  current  concepts 
of  evolutionary  zoogeography. 

Ranges  of  the  Individual  Species 

Four  species  of  nudibranch  occur  cir- 
cumtropically;  they  are  all  pelagic.  These  species 
are  Phylliroe  biicephala  "Peron  and  Lesueur, 
1810,"  Cephalopyge  trematoides  (Chun,  1889), 
Fiona  pinnata  (Ek;hscholtz  in  Rathke,  1831),  and 
Glaucus  atlanticus  Forster,  1777. 

Although  some  of  the  remaining  species  that 
comprise  the  data  base  for  Table  1  may  be  able  to 
swim  periodically  as  adults,  none  are  pelagic 
after  metamorphosis  from  the  veliger  stage.  In 
the  following  paragraphs,  the  distribution  of  each 
species  in  the  Panamic  province  follows  the  loca- 
tions in  other  zoogeographical  provinces  from 
which  it  has  been  reported. 


Lobiger  souvertni  Fischer,  18.56.  Circumtropical 
(Baba,  1974).  From  tropical  west  America,  south- 
ern Baja  California  (Isla  San  Jose  and  near  Cabo 
San  Lucas);  Santa  Cruz,  Nayarit,  mainland  Mex- 
ico; Galapagos  Islands  (see  Larson  and  Bertsch, 

I'lil yhranchia  viride  (Deshayes,  1857).  Carib- 
bean (Ev.  Marcus  and  Hughes,  1974:  503-506). 
Gulf  roast  of  Baja  California;  Nayarit,  Me.xico; 
Galapagos  Islands  (Bertsch  and  Smith,  1973;  Fer- 
reira  and  Bertsch,  1975). 

Stiliger  fuscatus  (Gould,  1870).  The  distribution 
of  this  species  is  classed  as  one  of  the  "Miscel- 
laneous" types:  north  Atlantic  coast  of  the 
United  States;  tip  of  South  America;  south- 
eastern coast  of  Australia  (Thompson,  1973: 
240-243).  Puerto  Penasa),  Mexiro,  northern  Gulf 
of  California  (Ferreira  and  Bertsch,  1975).  This 
may  be  an  introduced  species  (.sp«,sm  Carlton, 
1975:  17). 


Dolnbella  auricularia  (Lightfoot,  1786).  Indo- 
Pacific;  Ecuador  and  Easter  Island  (Ev.  Marcus 
and  Er.  Marcus,  1970:  191).  Gulf  roast  of  southern 
Baja  California  (Steinbeck  and  Ricketts,  1941: 
171, 539-541;  MacFarland,  1966:  32-37). 

Aplysia  dactylomela  Rang,  1828.  Cir- 
cumtropical (Ev.  Marcus  and  Er.  Marcus,  1967: 
38).  Panama  (Pilsbry,  1895:  88-89;  Engel  and 
Hummelinck,  1936:  6). 

Aplysia  Juliana  Quoy  and  Gaimard.  1832.  Cir- 
cumtropical. Northern  Gulf  of  California  (Puerto 
Penasco,  Sonora,  Mexico)  to  Paita,  Peru  (Ev.  Mar- 
cus and  Er.  Marcus,  1967:  155-159;  Keen,  1971: 

Aplysia  parvula  Morch,  1863.  Circumtropical 
(Thompson,  1977:  110-112).  Gulf  of  California 
(Lance,  1971:  60-63). 

Dolabrifera  dolabrifera  (Rang,  1828).  Circum- 
tropical (Kay,  1964:  184-185).  Northern  Gulf  of 
California  to  Panama  (Bertsch,  1970a;  Ferreira 
and  Bertsch,  1975:  325);  Galapagos  Islands  (Sphon 
and  Mulliner,  1972:  149). 

Stylocheilus  longicauda  (Quoy  and  Gaimard, 
1824).  Circumtropical  (Ev.  Marcus  and  Er.  Mar- 
cus, 1967:  159-160).  Gulf  of  California  (Fanner, 
1967;  Bertsch.  1970b,  and  1973b). 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      59 


Berthellina  citrina  (Ruppell  and  Leuckart,  1828). 
Circumtropical  (Thompson.  1970:  190-192;  1976a: 
167-169).  Southern  California;  throughout  the 
Gulf  of  California;  Galapagos  Islands  (Bertsch, 
1970b;  Lee  and  Brophy.  1969;  Sphon  and 
Mulliner.  1972:  150). 

Berthellina  quadridens  (Morch,  1863).  Carib- 
bean (Thompson,  1977:  105-106).  Panama  Bay, 
Pacific  coast  (Ev.  Marcus  and  Er.  Marcus,  1967: 

Pleura branchus  areolatum  (Morch,  1863). 
Caribbean  (Er.  Marcus  and  Ev.  Marcus,  1970:  55), 
south-central  Atlantic  (Ascension  Island; 
Rosewater,  1975:  25),  and  west  Africa  (Edmunds, 
1968:  85).  Northern  Gulf  of  California  (Puerto 
Penasco,  Sonora,  Mexico)  to  Panama;  Galapagos 
Islands  (Bertsch  and  Smith,  1973:  169). 


Berghia  major  (Eliot,  1903)  (includes  Baenlidin 
amnkusana  Baba,  1937).  Indo-Pacific  (Edmunds, 
1969:  467);  Oahu,  Hawaii  (pers.  obser.,  August 
1977).  Gulf  of  California  (Farmer,  1966;  Ferreira 
and  Bertsch,  1975:  328-329). 

Doriopsis  viridis  Pease,  1861.  Indo-Pacific 
(Young,  1967:  160-161).  Southern  Gulf  of  Califor- 
nia; known  only  from  1  specimen  (Bertsch,  1971). 

SpuriUa  alba  (Risbec,  1928).  Indo-Pacific  (Ed- 
munds, 1969:  465-466).  Coast  of  mainland  Mexico, 
from  near  Guaymas,  Sonora,  to  Punta  Mita, 
Nayarit  (Sphon,  1971, 1978). 

The  four  circumtropical  nudibranchs  are 
pelagic.  They  were  treated  in  a  previous  section. 

Cadlina  evelinae  Marcus,  1958.  Caribbean: 
Brazil  and  Jamaica  (Thompson,  1977:  pit.  2;  Ev. 
Marcus,  1977:  9).  Pacific  coast  of  Baja  California; 
Gulf  of  California  (Ev.  Marcus  and  Er.  Marcus, 
1967:  168-170). 

Dendrodoris  krebsii  (Morch,  1863).  Caribbean 
(Meyer,  1977:  304).  Northern  Gulf  of  California  to 
Panama;  Galapagos  Islands  (Bertsch,  1973b:  109; 
Meyer,  1977). 

Pkidiana  lynceus  Bergh,  1867.  Caribbean  (Ed- 
munds, 1964:  16-18).  Pacific  coast  of  Panama  Ca- 
nal Zone  (Ev.  Marcus  and  Er.  Marcus,  1967:  111- 

Spurilla  neapolitana  (Delle  Chiaje,  1823). 
Caribbean  and  Mediterranean  (Ev.  Marcus  and 

Er.  Marcus,  1967:  118-119).  Gulf  of  California 
(Alex  Kerstitch, pers.  comm.). 

Tayiiva  ketos  Marcus  and  Marcus,  1967.  Carib- 
bean (different  subspecies;  Er.  Marcus  and  Ev. 
Marcus,  1970:  65-66).  Northern  Gulf  of  California 
to  Bahia  de  Banderas,  Nayarit,  Mexico  (Ferreira 
and  Bertsch,  1975:  327). 

The  remaining  3  species  of  nudibranchs  have 
"Miscellaneous"  distributions  (i.e.,  they  are  not 
Panamic-Indo-Pacific,  Panamic-circumtropical, 
nor  Panamic-Caribbean). 

Aeolidiella  takanosimensis  Baba,  1930.  Japan 
(Baba,  1930);  Mediterranean  (Schmekel,  1968: 
122-123);  Oahu,  Hawaii  (pers.  obser.;  1  specimen, 
Wailupe,  19  May  1977;  7  specimens,  Earthwatch 
team  members,  Hauula,  14  June  1978).  Southern 
California  (Sphon,  1971);  Bahia  San  Marte,  Baja 
California  del  Sur,  Mexico  (Ferreira  and  Bertsch, 
1975:  329).  This  is  possibly  an  introduced  species 
to  Hawaii  and  the  eastern  Pacific. 

Coryphellina  rubrolineata  O'Donoghue,  1929. 
Suez  Canal,  Australia,  Japan,  Brazil.  San 
Agustin,  Sonora,  Mexico  (Ev.  Marcus  and  Er. 
Marcus,  1970:  210-211). 

Limenandra  nodosa  Haefelfinger  ^and  Stamm, 
1958.  Mediterranean;  Caribbean.  Bahia  Las  Cruces, 
Baja  California  del  Sur,  Mexico  (Bertsch,  1972). 


I  am  grateful  to  The  Center  for  Field  Research 
for  a  grant  that  enabled  me  to  collect  specimens 
in  Hawaii  during  June  1978.  I  thank  especially 
the  following  members  of  the  Hawaiian  Mollusks 
1978  Earthwatch  team  who  collected  specimens 
reported  in  this  paper:  Brian  McElaney,  Steve 
Norton,  Larry  Targett,  Gregg  Wilson,  and  Dr. 
Mel  Brophy.  I  also  thank  Alex  Kerstitch  for  sup- 
plying data,  and  Dr.  William  K.  Emerson  for 


Baba,  Kikutaro.  1930.  Studies  on  Japanese  nudibranchs  (3).  A. 

Phyllidiidae.  B.  Aeolididae.   Venus  2(3):   117-125;  pi.  4;  5 

text  figs.  (10  December  1930) 
.    1974.    Some    comments    on    Lobxger   souverbii 

Fischer.    1856,    re-identified,    of   Japan    (Opisthobranchia: 

Sacoglossa:  Lobigeridae).  The  Veliger  16(3):  253-257;  3  text 

figs.  (1  January  1974) 
Bertsch.  Hans.  1970a.  Dolabrifera  dolabrifera  (Rang,  1828): 

Range  extension  to  the  eastern  Pacific.  The  Veliger  13(1): 

110-111;  1  text  fig.  (IJuly  1970) 

60      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

.  1970b.  Opisthobranchs  from  Isla  San  Francisco, 

Gulf  of  California,  with  the  description  of  a  new  species. 
Gmtrib.  Sri..  Santa  Barbara  Mm.  Nat.  Hist,  t  1-16;  13  text 
figs.  (1  December  1970) 

.     1971.     Natural     histun'     and     occurrence     of 

opisthobranchs  of  Las  Cruces,  Baja  California,  Mexico,  and 
vicinity.  Abstr.  Proc.  Third  Ann.  Meet.  West.  Soc.  Malac., 
The  Echo  3: 16.  (7  March  1971) 

_.  1972.  Two  additions  to  the  opisthobranch  fauna 

of  the   southern    Gulf  of  California.    The    Veliger   15(2): 
103-106;  1  pi.;  3text  figs.  (1  October  1972) 
1973a.    Zoogeography    of   opi.sthobranchs    from 

tropical  west  America.  Abstr.  Proc.  Fifth  .Ann.  Meet.  West. 
Soc.  Malac..  Vie  Echo  5:  47-.54.  (.5  March  1973) 

1973b.    Distribution    and    natural    history    of 

opisthobranch  gastropods  from  Las  Cruces.  Baja  California 
del  Sur.  Mexico.  The  Veliger  16(1):  105-111;  2  maps.  (1  .July 
and  Alberic  A.  Smith.  1973.  Observations  on  three 

opisthobranchs  (MoUusca:  Gastropoda)  of  the  La  Paz  area. 
Baja  California,  Mexico.  Southwestern  Naturalist  18(2): 
165-176;  1  text  fig.  (29  June  197,3) 

Carlton.  James  T.  197.5.  Introduced  intertidal  invertebrates. 
In:  R.  I.  Smith  and  J.  T.  Carlton  (ed.).  Light's  Manual:  In- 
tertidal Invertebrates  of  the  Central  California  Coast. 
University  of  California  Press,  pp.  17-25  (8  May  197.5) 

Eximunds.  Malcolm.  1964.  Eolid  moUusca  from  Jamaica,  with 
descriptions  of  two  new  genera  and  three  new  species.  Bull 
Mar  Sri.  Gulf  Carib.  14(1):  1-.32;  16  te.xt  figs.  (19  March  1964) 

1968.   Opisthobranchiate  mollusca   from   Ghana. 

Proc.  Malac.  Soc.  London  38(1):  83-100;  12  text  figs.  (April 

1969.  Opisthobranchiate  mollusca  from  Tanzania. 

I.  Eolidacea  (Eubranchidae  and  Aeolidiidae).  Proc.  Malac. 

Soc.  Lond.  38(.5):  451-469;  10  text  figs.  (August  1969) 
Einerson.  William  K.  1978.  Mollusks  with  Indo-Pacific  faunal 

affinities  in  the  Eastern  Pacific  Ocean.  The  Nautilus  92(2): 

91-96.  (27  April  1978) 
Engel,  Hendrick,  and  P.  Wagenaar  Hummelinck.  19.36.  Ueber 

westindische  Aplysiidae  und  Verwandten  anderer  Gebiete. 

Capita  Zoologica  8(1):  1-76;  43  text  figs. 
Farmer,    Wesley    M.    1966.    Range    extension    of    Berghia 

amakusana  (Baba)  to  the  east  Pacific.  The  Veliger  9(2):  251; 

1  text  fig.  (1  October  1966) 
.    1967.    Notes   on    the   opisthobranchia    of   Baja 

California.  Mexico,  with  range  extensions.  —II.  The  Veliger 

9(3):  ^0-:}42;  1  text  fig.  (1  .January  1967) 
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1  text  fig.  (1  April  1975) 
Franz,  David  R.  1970.  Zoogeography  of  northwest  Atlantic 

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(October  1970) 
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79-83;  3  te.xt  figs.  ( I  .luly  1975) 
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Keen,  A.  Myra.  1971.  Sea  Shells  of  Tropical  West  America: 
marine  mollusks  fi-om  Baja  California  to  Peru.  Stanford 
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22(.«lor  pis.  (1  September  1971) 

I.ance.  .James  R.  1971.  Observations  on  the  sea  hare  Aplysia 
parvula  (Gastropoda;  Opisthobranchia)  from  the  Gulf  of 
California.  The  Veliger  14(1):  60-63;  4  text  figs.  (1  July 

Larson,  Mary,  and  Hans  Bertsch.  1974.  Northward  range  ex- 
tensions for  Lobiger  smiverhii  (Opisthobranchia:  Sacoglossa) 
in  the  eastern  Pacific.  The  Veliger  17(2):  22.5.  (1  October 

Lee,  Richard  S.,  and  Patrick  Brophy.  1969.  Additional 
bathymetric  and  locality  data  for  some  opisthobranchs  and 
an  octopus  from  Santa  Barbara  County,  California.  The 
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MacFarland.  Frank  Mace.  1966.  Studies  of  opisthobranchiate 
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Marcus,  P'rnst,  and  Eveline  du  Bois-Re.vmond  Marcus.  1970. 
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regions.  Stud.  Fauna  Curacao  Carib.  Isl.  33(122):  1-129;  160 
text  figs. 

Marcus,  Eveline  du  Bois-Re>'mond.  1977.  An  annotated 
checklist  of  the  western  Atlantic  warm  water  opistho- 
branchs. Jm^r.  Moll.  Studies  Suppl.  4:  1-22  (November  1977) 

,  and   Helen   P.   I.   Hughes.   1974   Opisthobranch 

mollusks  from  Barbados.  Bull.  Mar.  Sri.  24(3):  498-532;  56 
text  figs.  (27  November  1974) 

,  and  Ernst  Marcus.  1967.  American  opisthobranch 

mollusks.  Studies  in  Tropical  Oceanography  (U'niv.  Miami 

Inst.  Mar.  Sci.,  Miami.  Florida),  no.  6:  viii  -t-  256  pp.;  figs. 

1-155  -I-  1-95.  (22  December  1967) 
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Mexico.    Malacologui    10(1):     181-223;    93    text    figs.    (14 

November  1970) 
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bean ojast  of  the  Panama  Canal  7/me.  Bull.  Mar.  Sri.  27(2): 

299-.307;  4  te.xt  figs.  (27  April  1977) 
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262 pp.;  74  pis. 
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Caribbean  coast  of  southeastern  Panama.  Ti'ans.  San  Diego 

Soc.  Nat.  Hist.  15(14):  229-236;  1  te.xt  fig.  (27  June  1969) 
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mollusks    of    Ascension    Island.    South    Atlantic    Ocean. 

Smithsonian  C(mtrib.  Zool.  189:  iv  -I-  41  pp.;  24  te.xt  figs. 

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Nudibranchia  im  litoral  des  Golfes  von  Neapel.  Rev.  Suisse 

Zool.  75(1):  ia3-155;  21  text  figs.  (March  1968) 
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eastern  Pacific.  Tlir  Vrluirr  13(4):  :i58-:«t.  (1  April  1971) 
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1928)  (Mollusca:  Opisthobranchia).  The  Veliger  21(2):  305.  (1 

October  1978) 
and  David  K.  Mulliner.  1972.  A  preliminary  list 

of  known  opisthobranchs  from  the  Galapagos  Islands  col- 
lected by  the  Ameripagos  Expedition.  The  Veliger  15(2): 
147-1.52;  1  map  (I  October  1972) 

Vol.  93  (2-3) 

April  23. 1979 

THE  NAUTILUS      61 

Steinbeok.  John,  and  Edward  F.  Ricketts.  1941.  Sea  ofCoriez. 

Tne    \'ikinR    Press.    New    York,    x    +    .598   pp.;    40   pis. 

Thompson.  Thomas  E.  1970.  I>;ast^rn  Australian  Pleurobranch- 

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160(2):  173-198;  1  pi.;  11  text  figs.  (16  February  1970) 
1973.    Sacoglossan    gastropod    molluscs    from 

eastern  Australia.  Proc.  Malac.  Soc.  Lond.  40(4):  239-2.51;  3 

te.xt  figs.  (April  1973) 
.  1976a.  Biologj-  of  opisthobranch  molluscs.  Vol.  1. 

1976b.    Introduction:    Zoogeography    of    nudi- 

branchs.  Jour.  Moll  Shulies.  42(2):  295-:3()2  (pagination  in- 
cludes several  papers  by  various  authors).  (.August  1976) 

1977.  Jamaican  opisthobranch  molluscs  I.  Jnur. 

The  Ray  Society,  London.  207  pp.;  21  pis.;  106  text  figs. 

Moll.  Studies  43(2):  93-140;  3  pis.;  32  text  figs.  (July  1977) 

Young,  David  K.  1967.  New  records  of  nudibranchia 
(Gastropoda:  Opisthobranchia:  Nudibranchia)  from  the  cen- 
tral and  west-central  Pacific  with  a  description  of  a  new 
species.  The  Veliyer  10(2):  1.59-173;  18  text  figs.  (1  October 


Melissa  A.  Barbour 

1839  9th  Street 
Alameda.  CA  94501 

The  distribution  and  food  preference  of  the  nudibranch,  Cadlina  laevis  (Linnaeus. 
1767)  are  discussed.  This  species  has  an  amphiatlantic  distribution  from  Cape  Cod 
on  the  American  coast  to  the  Mediterranean  on  the  European  coast.  It  appears  to 
feed  on  the  soft,  dendroceratid  sponge,  Halisarca  dujardini  Johnston. 

The  dorid  nudibranch  Cadlina  laevis  (Linnaeus, 
1767)  has  an  amphiatlantic  distribution.  Lemche 
(1938)  reported  the  distribution  of  C.  laevis  ".  .  . 
from  the  Gulf  of  Mexico,  Greenland,  several 
localities  in  the  Arctic  Sea,  the  Faroes,  the 
Shetlands,  the  whole  coast  of  Norway,  south- 
wards along  the  west  coasts  of  Europe,  and  from 
the  Mediterranean."  The  inclusion  of  the  Gulf  of 
Mexico  in  this  list  is  probably  an  error  since 
Franz  (1970)  reported  the  southern  limit  of  this 
boreo-subarctic  species  to  be  Cape  Cod,  Massa- 
chusetts. There  are  no  reports  of  C.  laevis  from 
the  Gulf  of  Mexico  in  the  recent  literature.  It  is 
probable  that  Lemche  meant  the  "Gulf  of  Maine" 
where  this  species  does  occur.  While  a  student  at 
Northeastern  University,  Boston,  Massachusetts,  I 
made  field  observations  on  this  species  at  East- 
port,  Maine,  in  August  and  September  of  1969 
and  1970,  and  carried  out  laboratory  studies  at 

'.  Osntribution  no.  69.  Marine  Science  Institute,  Northeastern 
University.  Nahant,  Massachusetts. 

the  Marine  Science  Institute  at  Nahant,  Massa- 


C.  laevis  is  found  in  the  lower  intertidal  to 
subtidal  regions  of  exposed  rocky  coastal  areas.  It 
was  observed  by  me  under  rocks  at  approximate- 
ly -3.0  feet  below  mean  low  water  (MLW).  The 
habitat  consisted  of  boulders  resting  on  bedrock 
around  and  imder  which  small  amounts  of  sandy 
mud  were  trapped.  Some  algal  growth  was  pre- 
sent on  the  boulders.  Other  invertebrates,  in- 
cluding brachiopods,  colonial  and  solitary 
tunicates,  and  sponges,  were  also  attached  to  the 
underside  of  these  boulders.  TTie  unspiculated 
dendroceratid  sponge,  Halisarca  dujardini; 
Johnston,  was  commonly  found  encrusting  the 
undersides  of  these  boulders.  C.  laevis  was 
observed  in  close  proximity  to  this  sponge,  being 
either  within  a  small  cleared  area  at  the  center 

62      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

of  a  Halimrca  mat  or  at  the  edge  of  it.  The 
anterior  mantle  of  the  nudibranch  typically  cov- 
ered the  edge  of  the  sponge  mat.  When  the  nudi- 
branch was  removed  a  concavity  in  the  edge  of 
the  sponge  was  seen.  This  concavity  conformed  to 
the  size  and  shape  of  the  anterior  portion  of  the 
dorid.  The  nudibranch  was  only  rarely  found  on 
rocks  without  the  sponge. 


Specimens  of  C.  laevis  were  kept  in  laboratory 
aquaria  for  up  to  10  months  without  any  obvious 
food  source.  During  this  time  the  animals  were 
observed  to  release  fecal  strands  and  to  spawn. 
Animals  dissected  during  this  period  had  a  brown 
material  in  the  stomach.  I  believe  this  material 
was  alagal  slime  from  the  sides  of  the  aquaria  on 
which  the  nudibranchs  were  able  t*j  maintain 
themselves.  Eggs  were  deposited  in  early  spring. 
The  young  hatched  after  approximately  2  months, 
but  did  not  mature.  When  //a/ isarra -encrusted 
rocks  were  placed  in  the  aquaria  the  nudibranchs 
were  observed  to  feed  on  the  sponge  (M.  P.  Morse, 
pens,  cornm.). 


Two  of  Swennen's  (1961)  three  criteria  for 
determining  preferred  food  of  nudibranchs  were 
met  in  this  study:  (1)  the  animal  was  found  in 
the  field  in  close  conjunction  with  the  probable 
food;  and  (2)  the  animal  fed  on  the  probable  food 
in  the  laboratory.  The  third  criterion,  the  main- 
tenance of  the  animal  on  the  preferred  food  in 
the  laboratory,  was  not  met  in  this  study. 

There  are,  in  addition  to  the  above  field  and 
laboratory   observations,   morphological   and 

anatomical  indications  that  C.  Inei-U  feeds  on  soft 
sponges.  The  body  is  oval,  with  a  broad  foot  and 
wide  radula;  the  mouth  lacks  true  mandibles.  The 
digestive  tract  lacks  a  buccal  pump,  has  a 
reduced  caecum,  and  there  is  a  reduction  in  the 
number  of  gland  cells  throughout  the  tract  (Bar- 
bour, 1;)71).  These  modifications  have  been  pre- 
viously described  for  feeders  of  soft  sponges  by 
Forrest  (1953)  and  by  Thompson  (1962). 


I  wish  to  thank  Dr.  M.  P.  Morse  and  Dr.  N.  W. 
Riser  for  their  help  and  support  during  the 
preparation  of  this  manuscript  and  Dr.  Welton  L. 
Lee,  David  R.  Lindberg  and  James  E.  Sutton  for 
their  reviews  and  comments  on  it.  Part  of  this 
study  was  submitted  in  partial  fulfillment  of  the 
requirements  for  a  MS  degree  at  Northeastern 


Barbour.  M.  A.  1971.  The  functional  morphology  of  the 
digestive  tract  of  the  dorid  nudibranch.  Cadlina  laevis 
Bergh,  1879  [sic].  Unpublished  MS  thesis.  Northeastern 
University,  Boston,  Massachusetts.  64  pp. 

Forrest,  J.  E.  1953.  On  the  feeding  habits  and  morphology  and 
mode  of  function  of  the  alimentary  canal  in  some  littoral 
dorid  Nudibranchiata  Mollusca.  Proc.  Linn.  Snr.  London 
164(2):  225-2a5. 

Franz,  D.  R.  1970.  Zoogeography  of  Northwest  Atlantic 
opisthobranch  molluscs.  Afar.  Biol.  7:  171-180. 

Lemche,  H.  1938.  Gastropoda  opisthobranchiata.  77i€  Zoology 
of  Iceland  4(51):  1-54. 

Swennen,  C.  1961.  Data  on  distribution,  reproduction  and 
ecolog>'  of  the  nudibranch  molluscs  occurring  in  the 
Netherlands.  A'eMer/(i«(is ,/.  Sea  Rejteuirh  1:  191-240. 

Thomiwon,  T.  E.  1962.  Grazing  and  the  life  c.vcle  of  British 
nudibranchs.  In:  Grazing  in  Terr&strial  and  Marine  En- 
vironments, Ed.  D.  J.  Crisp.  Sijmp.  British  Ecol.  Soc.,  4: 

Specimen  Shells 

Offering  microscopic  and  miniature  (to  ';  inch)  shells  from 
the  Florida  Keys,  with  accurate  locality  data.  Also  unsorteH 
grunge;  write  for  list. 

Margaret  Teskcy 

P  0.  Box  J7.i 

B)!i  PineKeii.  Fl  -I.Hii.i 

Rare  and  Exotic  Specimen  Shells 
for  the  discriminating  collector 
Free  price  list 



M6  Ralph  Avenue 

Bnsoklyn,  New  York  11236  USA 

(212)    m-S550 


•  ••I 

Vol.  93  (2-3) 

April  23.  1979 

THE  NAUTILUS      63 



Dorothea  S.  Franzen 

Illinois  Wesleyan  University 
Bloomington,  Illinois  61701 

Catinella  parallela,  a  new  sppcies  of  Siwcineidae.  mid  its  reproductive  oryans. 
chninioiiomeii.  shell  and  detailed  habitats  are  described.   The  knoum  geographic 
range  extends  from  western  Elinois  to  western  Indiana,  between  38°10'  -  J^O'SO'N 
latitude.  This  species  was  taken  from  three  types  of  habitats. 

In  the  coui-se  of  my  field  studies  on  succineid 
gastropods  in  the  midwestem  states  I  have  found 
a  large,  hitherto  undescribed  species. 

Catinella  parallela  n.  sp. 

Description  of  Holotype:  Shell:  amber-colored, 

translucent,  imperforate,  elongate-ovate,  com- 
posed of  three  and  one-third  inflated  whorls 
separated  by  a  deeply  incised  suture;  height  10 
mm,  width  6.1  mm.  A  knoblike  nuclear  whorl 
tops  the  acute  spire;  whorls  increase  rapidly  in 
size  resulting  in  a  tumid  ultimate  whorl;  nuclear 


FIG.  1.  A,  B,  Hntotype  of  Catinella  parallela,  n.  sp.  (Height. 
10  mm).  C.  Paratype  of  Catinella  parallela  n.  sp..  one-half 
mile  X.  White  River.  Knox  County.  Indiana  (Height  11.7 
mm).   D.  Paratype  of  Catinella  parallela  n.  sp..  Pere  Mar- 

quette State  Park,  Jersey  County.  Illinois  (Height  12.0  mm). 
E.  F.  Paratyi>e  of  Catinella  parallela  n.  sjh.  AVw  Hardin, 
Greene  County.  lUinoi.':  (Height  1-1.2  mm.) 

64      THE  NAUTILUS 

April  23,  1979 

Vol.  93  (2-3) 

whorl  finely  granular;  irregularly-spaced  longi- 
tudinal striations,  fine  on  the  lower  half  of  the 
nuclear  whorl,  increasing  gradually,  becoming 
coarser  towards  the  aperture;  ovate  aperture  oc- 
cupies nearly  seven-tenths  of  height  of  shell 
(Table  1).  Sharply-edged  peristome  very  fragile; 
very  thin  callus  discernible  on  ultimate  whorl 
above  the  aperture;  amber-colored  columella 
follows  inner  border  of  peristome  and  curves  as  it 
disappears  into  the  ultimate  whorl  (Fig.  1,  A). 

Body  and  Mantle  Surfaces:  Surface  of  head 
and  body  wall  cream-colored,  coarsely  and  ir- 
regularly tuberculate;  pigmentation  of  dorsal 
body  surface  consists  of  bands  of  dark  flecks  ex- 
tending from  anterior  end  of  head  to  junction  of 
mantle  and  the  body  wall;  mid-dorsally  on  head 
pigmentation  forms  a  triangle,  narrowing  to  a 
band  between  the  superior  (posterior)  tentacles, 
dividing  and  continuing  as  a  double  band  mid- 
dorsally  the  length  of  the  body;  the  median 
triangle  flanked  on  either  side  by  a  dark  band, 
bending  medially  around  the  superior  tentacles, 
paralleling  the  dorsal  pair  the  length  of  the  body; 
median  triangle  flanked  on  either  side  by  a  dark 
band  which  bends  medially  around  the  superior 
tentacle  to  parallel  the  mid-dorsal  pair  the  length 
of  the  body;  surface  of  both  pairs  of  tentacles 
flecked;  pigmentation  of  lateral  body  wall  form- 
ing a  broad  horizontal  band. 

The  genital  aperture,  about  0.5  mm  in  length, 
surrounded  by  a  white  lip,  situated  on  anterior 
right-hand  side  of  body.  On  either  side  a  pedal 
groove,  continuous  from  labial  palp  to  posterior 
tip  of  body,  separates  foot  from  lateral  body  wall; 
pedal  groove  paralleled  by  a  less  pronounced 
suprapedal  groove.  Shallow,  vertical  grooves  in- 
cise the  suprapedal  and  pedal  grooves,  margin  of 
foot  and  the  broad  pigmented  band.  These  ver- 
tical grooves  produce  shallow  scallops  along  the 
margin  of  the  foot  especially  when  the  animal  is 
in  a  somewhat  contracted  state.  The  sole  of  the 
foot  is  cream -colored  and  unpigmented. 

The  mantle  collar  is  flecked  overall.  From 
anterior  margin  of  mantle  narrow  bands  of  pig- 
ment, distinct  near  edge  of  collar,  merge  forming 
streaks  over  mantle  surface.  The  kidney  is  out- 
lined by  a  dark  band. 

Holotype:  Catalogue  no.  FMNH  201444; 
Paratypes  nos.:   FMNH  201445,   FMNH  201446, 

Molluscan  Collection,  Field  Museum  of  Natural 
Histor>',  Chicago,  Illinois.  Additional  paratypes 
are  in  the  private  collection  of  the  author. 

T)fncripti(in  of  Paratifpes:  Shell:  (Fig.  1,  C-F) 
Shells  of  mature  snails,  attaining  a  height  of  15.2 
mm,  are  comprised  of  3  1/4  to  3  3/4  inflated 
whorls.  Dimensions  of  the  three  largest  shells, 
number  of  shells  measured,  and  the  median  of 
each  of  the  nine  series  measured,  are  recorded  in 
Table  1.  The  range  of  the  greatest  height  of  the 
series  of  shells  included  in  this  study  is  from  10.2 
to  15.2  mm,  and  the  range  of  the  greatest  width 
is  from  ■6.0  to  8.28  mm.  The  largest  apertures  of 
the  shells  of  the  nine  series  occupy  from  65.8  to 
72.0  percent  of  the  entire  height  of  the  shell. 
Other  dimensions  and  relative  dimensions  are  to 
be  noted  in  Table  1.  T^e  largest  shells  were  taken 
from  the  flood  plain  of  the  Illinois  River,  New 
Hardin,  Green  County,  Illinois  (Field  #269)  on 
June  22,  1966.  To  date  I  have  not  found  mature 
snails  sundving  beyond  the  month  of  July. 

Reproductive  Organs:  (Fig.  2)  The  albumin 
gland  (A,  C  -  AG)  triangular  in  form,  composed 

of  fine  acini,  is  enclosed  within  a  thin,  tran.'^- 
parent  sheath.  The  elongate,  sube(iually  biiobed 
seminal  vesicle  (A,  C  -  SV)  is  enclosed  with- 
in a  thin,  transparent,  pigmented  sheath.  The 
darkly  pigmented  hermaphroditic  duct  (A,  C  - 
HD)  and  the  bilobed  seminal  vesicle  join  to  form 
the  fertilization  sac  (A,  C  -  FS)  from  which 
diverge  the  oviduct  (OD)  and  the  sperm  duct  (SD) 
which  leads  into  the  prostate  gland  (PG).  The 
oval  prostate  gland,  enclosed  by  a  thin, 
transparent,  pigmented  sheath,  is  composed  of 
acini  which  are  coarser  than  those  of  the  albumin 
gland.  The  length  of  the  prostate  gland  exceeds 
that  of  the  albumin  gland  (A,  C).  As  the  vas 
deferens  approaches  the  penis  from  the  prostate 
gland  it  follows  the  penis  along  its  dorsal  surface. 
As  it  enters  the  distal  end  of  the  penis  it  enlarges 
to  form  the  epiphallus  (B,  C  -  EP)  which  enters 
the  unsheathed  penis  (P)  terminally.  The  penis 
enlarges  immediately  into  a  cylindrical  form.  The 
penial  appendage  (B,  C  -  PA)  whose  base  is 
almost  one-half  the  length  of  the  penis,  originates 
subterminally  where  the  penis  joins  the  genital 
atrium  (B,  C  -  GA).  The  appendage  expands 
horizontally   to   equal    about   two-thirds   of  the 

Vol.  93  (2-3) 

April  23,  1979 

THE  NAUTILUS      65 

TABLE  1.  Dimensioris  of  shells  o/Catinella  paiallela,  ii.  »p.  The  measiirements  are  of  the  three  largest  shells  of  each  of  the  9  series 
(6  liicntities)  as  indicated,  hi  the  J,lh  column  of  iieasnrentents  are  listed  the  mtios  of  the  uidth  of  the  shell  over  its  height.  In  the 
last  S  columns  air  listed  the  ratios  of  the  height  of  the  aperture  over  the  height  of  the  shell,  iridth  of  aperture  over  width  of  shell 
width  ofapeiture  oiwr  height  of  aperture. 




Height  of 

Width  of 

H.    Ap./ 

W.   Ap./ 

W.   Ap./ 







H.    Shell 

W.   Shell 

H.    Ap. 




10. 0  mm 

6. 1   mm 


6.7  nun 

4.1  mm 




Type  Locality 











Field  «4S8 











Floodplain.   Wabash  R. 


White  Co. ,   Illinois 

June  20,  1977 

Range   (6  shells) 



7.5   - 


.56-. 62 



.66-. 72 



.59-. 62 










Field  •458 











Floodplain,   Wabash  R. 

,    3 










Wiite  Co. ,   I llinois 











June  5,   1976 

Range  {12  shells) 



6.3  - 


.53-. 628 



.623-. 711 

.    .672- 


.606-. 717 










Field   »461 











One-half  mi.   S  of 











White  River,   Knox  Co. 

,   3 











June  6,    1976 

Range   (8  shells) 







.521-. 663 



.585-. 678 



.662-. 735 










Field  »461 











One-half  mi.   .N  of 











White  River,   Knox  Co. 

,    3 











June  21,   1977 

Range   (28  shells) 





.49-. 64 



.56-. 70 



.56-. 66 










Field  "462 



12.84  mm 

7.25  mm 


7.83  mm 

5.26  mm 




10  mi.   N     Vincennes, 











Knox  Co. ,    Indiana 











June  6,    1976 

Range   (20  shells) 





.474-. 643 



.528-. 658 



.576-. 843 










Field  »187 











Pere  Marquette  State 











Park,  Jersey  Co. . 












June  IS,    1954 

Range   (7  shells) 






.56-. 61 



.60-. 69 



.57-. 66 










Field  •269 











New  Hardin, 











Greene  Co.,   Illinois 










July  11,    1964 

Range   (25  shells) 








.606-. 711 



.602-. 723 










Field  1269 











New  Hardin, 











Greene  Co. ,    Illinois 











June  22,    1966 

Range   (9  shells) 



10. so- 



ls.  30 


.527-. 630 



.618-. 689 



.630-. 777 










Field  11445 




6. 85 


7.  SO 





0.8  mi.    S     Nutwood, 











Jersey  Co. ,    Illinois 







4. 52 




June  1,    1975 

Range   (14  shells) 




S. 08-7. 00 




.610-. 708 



. 596- . 72 










66      THE  NAUTILUS 

April  23,  1979 

Vol.  93  (2-3) 

FIG.  2.  Reproductive  organs  o/Catinella  parallela  n.  sp.  AG. 
albumin  gland:  EP,  epiphalhis:  FS,  fertilization  sac:  GA. 
genital  atrium:  HD,  hermaphroditic  duct:  OD,  oviduct:  P. 
penis:  PA,  penial  appendage:  PG,  prostate  gland:  PRM,  penial 
retractor  muscle:  SD,  sperm  duct:  SP,  spermaiheca:  SPD, 
spermathecal  duct;  SV,  semina/  vesicle;  VA,  vagina;  VD,  ytw 

length  of  the  penis  —  the  expanded  portion  paral- 
lels the  penis  (A,  C).  The  vertical  dimension  of 
the  appendage  is  almost  twice  that  of  the  body  of 
the  penis.  The  internal  walls  of  the  penis  and  of 
the  appendage  are  folded  forming  very  prominent 
ridges  projecting  into  the  lumen.  The  internal 
foldings  of  the  appendage  can  be  noticed  exter- 
nally by  markings  as  indicated  (B,  C).  Fibers  of 
the  broad,  stout  penial  retractor  muscle  insert 
mainly  onto  the  base  of  the  penial  appendage; 
lesser  fibers  insert  onto  the  penis  and  onto  the 

The  globular  spermatheca  (Fig.  2,  C  -  SP)  is 
connected  to  the  vagina  by  a  stout  spermathecal 
duct  (SPD)  which  enlarges  as  it  approaches  and 
enters  the  vagina.  The  short  vagina  expands  as  it 
opens  into  the  genital  atrium  (B  -  GA). 

The  Radula:  Radulae  of  seven  paratypes  of 
three  localities  were  stained  and  mounted.  The 
number  of  rows  of  teeth  occurring  on  the  radulae 
examined  range  from  84-90  (Table  2).  There  are 
few  teeth  to  a  row  on  the  anterior-most  rows;  the 
number  increases  rapidly  posteriorly. 

The  number  of  marginals  and  laterals  of  rep- 
resentative rows  of  the  seven  radulae  are  re- 
corded in  Table  2.  Although  there  is  an  indi- 
vidual variation  of  the  radulae  and  also  of  the 
rows  of  teeth  of  a  radula,  the  ratio  of  marginals 
to  laterals  is  approximately  1:1  Such  a  ratio  is 
characteristic  of  the  genus  as  noted  by  Quick  to 
be  true  of  Catinella  (Sticcinea)  arenaria  ("B.-Ch.") 
(Quick.  19.33,  Fig.  4,  p.  296). 

The  structural  details  of  the  individual  teeth 
resemble  those  of  the  genus  as  described  for 
European  species  by  Quick  (ibid).  The  charac- 
teristics of  the  teeth  are  described  below  and  il- 
lustrated in  Fig.  3,  A.  The  central  tooth  (C)  bears 
a  broad  basal  plate  having  a  posterior,  serrated 
margin  flanked  on  either  side  by  a  rounded  boss. 
Ihe  pointed  mesocone  extends  downward  to  a- 
bout  the  lower  third  of  the  basal  plate.  A  short, 
I)ointed  ectocone  flanks  the  mesocone  on  either 

The  laterals  (L-L)  have  a  large,  pointed  meso- 
cone which,  like  that  of  the  central  tooth,  extends 
downward  to  about  the  lower  third  of  the  basal 
plate.  A  small,  pointed  endocone  is  present.  The 
singly  pointed  ectocone  is  sometimes  divided  into 
two  cusps;  this  is  especially  true  of  the  more 
lateral  teeth. 

The  marginals  (L-M)  smaller  than  the  laterals, 
have  a  basal  plate  which  is  broader  than  long; 
this  is  especially  true  of  the  outermost  marginals 
(Fig.  3).  The  small  endocone  is  pointed;  the 
pointed  mesocone  extends  to  the  base  of  the  basal 

T.\BLE  2.  Fonnulae  of  representative  rows  of  teeth  of  Cati- 
nella parallela  new  species. 

No.  of 




of  le 







Field  Ho. 









1  - 




Jersey  County, 






I  - 









I  - 









I  - 




Field  Ko. 













Seat  Hardin, 



























































Field  No. 











Knox  Coun 





-  ! 







-  1 









-  1 







-  1 




Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      67 

plate.  The  ectocone  of  the  inner-most  marginals  is 
divided  into  two,  while  the  outermost  is  divided 
into  three  cusps. 

The  basal  plates  of  the  marginals  are  short  and 
broad  which  is  a  distinctive  feature  of  the  genus 
Catinella  as  observed  by  Quick  (1933,  Fig.  4).  The 
basal  plates  of  the  marginals  of  the  radula  in  the 
genus  Oxyloma  are  long  and  tapering  as  reported 
of  Oxyloma  (Succinea)  pfeifferi  ("Rossm.")  by 
Quick  (ibid,  Fig.  1).  This  feature  of  the  radula 
was  observed  in  other  species  of  Oxyloma  by 
Franzen  (1963,  Fig.  1;  1966,  pp.  64-65;  1969,  Fig. 
1;  1973,  Fig.  4).  The  basal  plates  of  the  marginals 
of  the  genus  Succinea  are  intermediate  in  length 
(Quick,  1933,  Figs.  2,  3;  and  Franzen,  1959,  Fig.  3; 
1971,  Fig.  3). 

The  Jaw.  The  amber-colored  jaw  is  illustrated 
in  Fig.  3,  B.  Anteriorly  the  collar  has  a  median 
fold  flanked  on  either  side  by  smaller  lateral 
folds.  Posteriorly  the  collar  bears  a  broad,  median 

Chromosome  Number.  Ovotestes  of  Catinella 
parallela  were  squashed  and  stained  with  orcein. 
Examination  of  the  stained  chromosomes  in 
meiotic  metaphase  revealed  the  haploid  number 
of  six.  This  small  number  is  characteristic  of  the 
genus  Catinella  (Patterson,  1971,  Table  1.).  This 
contrasts  with  the  haploid  number  of  nineteen  of 
several  species  of  Oxyloma:  Oxyloma  deprimida 
Franzen  (Franzen,  1973,  Fig.  1,  and  p.  68);  0. 
retusa  (Lea),  0.  haydeni  (W.  G.  Binney)  and  0. 
salleana  (Pfeiffer)  (Franzen,  1966,  p.  67).  The 
haploid  chromosome  number  of  eighteen  is  char- 
acteristic of  Succinea  vaginacontorta  Lee 
(Franzen,  1971,  p.  141)  and  other  species  of  Siw- 
cinea  of  continental  USA.  (Patterson,  1971,  Table 


Geographic  Distribution  and  Habitats.  The 
known  geographic  range  of  Catinella  parallela  ex- 
tends from  the  flood  plain  of  the  Illinois  River  in 
Greene  and  Jersey  counties  in  western  Illinois, 
across  the  state  to  the  banks  of  the  Wabash  River 
in  White  County  in  eastern  Dlinois,  and  to  Knox 
County  in  western  Indiana.  The  eight  localities 
where  I  have  found  C  parallela  represent  three 
types  of  ecological  habitats,  namely:  (1)  a  wooded 
flood  plain  of  a  river;  (2)  a  slough  with  stands  of 
plants  including  Typha  sp.  (cattails),  Sagittaria 
latifolia  Willd.  (arrowhead),  Eleocharis  sp.  (spike 

rush).  Polygonum  ineum  Muhl  (water  smart- 
weed),  Rhus  radicans  L.  (poison  ivy),  and  Spar- 
tina  sp.  (sawgrass);  (3)  roadside  ditch  supporting 
a  stand  of  Typha  sp. 

Locality  1,  Type  Locality:  Field  No.  D.S.F.  458; 
western  edge  of  the  flood  plain  of  the  west  side  of 
the  Wabash  River,  below  the  bridge  of  Illinois 
Hwy.  14  (formerly  U.S.  Hwy  460),  7  miles  E 
Crossville,  White  County,  Illinois.  The  flood  plain 
is  a  woodland  of  predominantly  Acer  sac- 
charinum  L.  (silver  maple),  Gleditsia  triacanthos 
L.  (honey  locust),  and  Populus  deltoides  Marsh 
(cottonwood).  Catinella  parallela  lives  on  the 
shaded  damp  ground,  on  rotting  wood,  and  on 
dead  leaves  on  the  ground. 

Locality  2,  Field  No.  D.S.F.  459;  twelve  miles  E 
Princeton,  Gibson  County,  Indiana,  Indiana  Hwy. 
64,  one-half  mile  E  Wabash  River,  in  a  lowland 
wooded  area  of  predominantly  Acer  saccharinum 
L.  One  individual  of  Catinella  parallela  was 
under  a  piece  of  cardboard  in  a  small  pile  of  rub- 

Locality  3,  Field  No.  D.S.F.  460;  flood  plain  of 
the  Patoka  River,  Patoka,  Gibson  County,  In- 
diana, in  a  wooded  area  of  predominantly  Acer 
saccharinum  L.  and  Populus  deltoides  Marsh. 
Two  individuals  of  Catinella  parallela  were  found 
on  damp  ground  of  an  exposed  area. 

Locality  U,  Field  No.  D.S.F.  461;  one-half  mile 
N  White  River,  a  roadside  ditch  and  slough 
alongside  Orville  Road,  west  off  of  U.S.  Hwy.  41, 
Knox  County,  Indiana.  Typha  sp.  grows  in  the 


FIG.  3.  k:  Rfspresentative  radvla  teeth  o/ Catinella  parallela 
/(.  sp.  C,  central  tooth:  1-L-L,  Ut  left  lateml:  i-L-L.  ith  Icjl 
lateral:  U-L-L,  Uth  left  lateral:  1-L-M.  1st  left  marginal:  8- 
L-M.  Sth  left  marginal.  B:  A  jatr  o/'Catinella  parallela  n.  sp. 

68      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

water  while  Sagittaria  latifolia  Willd.  and  Spar- 
tina  sp.  grow  in  very  wet  ground.  Oxyloma 
salleana  (Pfeiffer)  lives  on  the  cattails  and  on 
dead  vegetation  floating  on  the  water.  Catinella 
parallela  lives  near  the  water's  edge  on  the  base 
of  cattails,  on  the  matting  of  dead  vegetation  and 
on  bare  spots  on  the  wet  ground  shaded  by  saw- 
grass  and  leaf  litter. 

Locality  5,  Field  No.  D.S.F.  467;  ten  miles  N 
Vincenes,  Knox  County,  Indiana,  roadside  ditch 
along  U.S.  Hwy.  41.  Although  at  the  time  this 
site  was  visited  the  water  was  becoming  polluted, 
TjfjAa  sp.  was  growing  in  the  ditch  and  Catinella 
parallela  was  still  living  there. 

Lncalitii  6.  Field  No.  D.S.F.  269;  eastern  bank 
of  the  Illinois  River  at  New  Hardin,  Greene 
County,  Illinois.  On  June  11,  1964,  the  ground 
was  muddy  from  recent  rains.  The  bank  sup- 
ported a  thicket  of  Salix  sp.  (willows).  Oxyloma 
salleana  (Pfeiffer)  lived  on  the  muddy  bank. 
Catinella  parallela  was  found  creeping  on  the  wet 
ground,  on  surfaces  of  wet  boards  and  other 
debris  on  the  ground  along  the  eastern  edge  of 
the  flood  plain  away  from  the  shore  of  the  river. 
Since  then,  as  a  result  of  severe  storms  and 
flooding,  the  entire  flood  plain  is  littered  with 
logs,  branches  and  other  debris.  The  habitats  of 
the  two  succineid  species  are  destroyed,  at  least 

Locality  7,  Field  No.  D.S.F.  445;  eight-tenths 
mile  S  Nutwood,  or  2.4  miles  S  from  the  junction 
of  Illinois  Hwy.  100  and  Illinois  Hwy.  16,  Jersey 
County,  Illinois,  on  the  west  side  of  Illinois  Hwy. 
100.  The  habitat  is  a  poorly  drained  slough.  The 
bottom  of  the  slough  consists  of  fine,  tan  sand, 
and  coarse,  sandy  reddish-tan  loess  from  the 
deposit  immediately  to  the  east.  The  slough  sup- 
ports growths  of  Typha  sp.,  Eleocharis  sp., 
Polygoneum  ineum  Muhl  and  RMis  radicans  L. 
Several  small  clumps  of  Popuhis  deltoides  Marsh 
and  a  thicket  of  Comus  drummondi  C.  A.  Meyer 
are  located  within  the  slough.  On  June  1,  1975,  a 
large  population  of  Oxyloma  salleana  (Pfeiffer) 
lived  on  Ti/i)ha  sp.  and  on  the  wet  ground  at  the 
base  of  the  cattails.  A  well-establi.shed  population 
of  Catinella  parallela  lived  on  the  eastern  edge  of 
the  slough  on  wet,  but  not  swampy,  ground  where 
the  vegetation  was  less  dense.  One  June  11,  1977, 

due  to  an  abnormally  low  amount  of  rainfall  dur- 
ing the  spring  months,  there  was  no  water  in  the 
slough  but  the  ground  was  still  damp.  0.  salleana 
was  feeding  on  cattails  and  spike  rish.  However, 
a  four-hour  search  netted  only  one  individual  of 
r.  parallela.  This  might  indicate  that  C  parallela 
is  more  readily  affected  by  adverse  conditions 
than  is  ().  salleana. 

Locality  8,  Field  No.  D.S.F.  187;  Pere  Mar- 
quette State  Park,  Jersey  County,  Illinois,  west 
side  of  Illinois  Hwy.  100.  The  site  is  the  east 
shore  of  a  lake  formed  by  a  bow  of  the  Illinois 
River.  On  June  15,  1954,  Oxyloma  salleana  (Pfeif- 
fer) and  Catinella  parallela  were  abundant  on  the 
wet  ground  and  on  wet  boards  lying  on  the  bank. 
I  have  visited  this  site  several  times  but  have  not 
found  C  parallela  since  1954,  although  0. 
salleana  is  still  well-established. 

Diagnostic  Features.  Shell:  the  elongate-ovate 
shell  is  comprised  of  3''4  to  3' :  tumid  whorls.  The 
height  of  the  ovate  aperture  exceeds  six-tenths  of 
the  height  of  the  shell.  Two  examples  of  the  latter 
are:  (a)  The  height  of  the  shell  of  the  holotype  is 
10.0  mm  and  its  aperture  6.7  mm  in  height ;  height 
of  aperture  /  height  of  shell  is  .67.  (b)  The  height  of 
the  largest  shell  of  the  series  studied  is  15.2  mm 
and  its  aperture  9.6  mm  in  height ;  height  of  aper- 
ture /  height  of  shell  is  .632.  The  amber-colored 
columella  forms  the  inner  border  of  the  peristome. 
A  thin  callus  is  discernible  on  the  ultimate  whorl 
above  the  aperture. 

Penis  and  Penial  Appendage:  the  base  of  the 
penial  appendage  equals  almost  half  the  length  of 
the  penis.  The  expanded  appendage  is  positioned 
parallel  to  the  penis.  The  vertical  dimension  of 
the  appendage  is  almost  twice  the  width  of  the 
body  of  the  penis.  The  penial  retractor  muscle 
inserts  mainly  onto  the  base  of  the  i^enial  appen- 
dage and  by  means  of  lesser  fibers  onto  the  penis 

The  specific  name  parallela  refers  to  the  ex- 
panded penial  appendage  being  parallel  to  the 
penis  instead  of  right  angle  to  the  penis  as  is 
characteristic    of    other    species    in    the    genus 


Spermatheca:  the  globular  spermatheca  is  con- 
nected to  the  vagina  by  a  stout  duct  which  en- 
larges as  it  approaches  and  enters  the  vagina. 

Vol.  9:1  (2-3) 

April  2:1  1979 

THP]  NAUTILUS      69 

Comparative  Remarks:  ('(it'meUn  piimUcla 
probably  more  nearly  resembles  C.  texana 
Hubricht  than  any  other  described  species.  The 
differences  include:  (a)  Shell  dimensions  and 
ratios  of  dimensions.  (1)  The  aperture  of  C. 
parallela  is  larger  in  proportion  to  the  height  of 
the  shell  than  it  is  in  C.  texana.  (2)  The  largest 
known  shell  of  C.  parallela  is  15.2  mm  in  height, 
(b)  The  penial  appendage  of  C.  parallela  is 
parallel  to  the  penis  whereas  in  C.  texana  the 
penial  appendage  is  vertical  in  position,  i.e.  at 
right  angle  to  the  penis,  (c)  The  penial  retractor 
muscle  of  C.  parallela  inserts  mainly  onto  the 
base  of  the  penial  appendage;  lesser  fibers  insert 
onto  the  penis  and  onto  the  epiphallus.  The  peni- 
al retractor  muscle  of  C.  texana  is  "connected  to 
the  side  of  the  penis  near  the  middle"  (Hubricht, 
1961,  p.  61).  (e)  The  spermathecal  duct  of  C. 
parallela  is  stout,  of  C.  texana  slender,  (f)  The 
seminal  vesicle  of  C.  parallela  is  pigmented  but 
not  as  darkly  as  described  of  C.  texana  as  being 
"strongly  pigmented,  almost  black"  (ibid). 


National  Science  Foundation  Grants-in-Aid 
No's.  NSF  G18000  and  NSF  GB2715  provided 
laboratory  equipment  and  supported,  in  part,  the 
field  studies.  Dr.  A.  Byron  Leonard  read  the 
manuscript  and  offered  helpful  suggestions. 


Franzen,  Dorothea  S.  1959.  Anatomy  of  Sitccinea  ovdis  Say. 

Pmc.  Mai.  Soc.  Lmidon  33(5,  Nov.) :  193-199,  tables  1-2,  figs. 

.  1963.  Variations  in  the  Anatomy  of  the  Succineid 

Gastropod  Ozyloma  retiisa.  The  Nautilvs  76(3):  82-95.  tables 

1-2,  figs.  1-4. 

1966.  Anatomy  of  the  Succineid  Gastropod  Ox- 

yloma  salleana  (Pfeiffer)  The  Nautilus  80(2):  59-69,  tables 
1-2,  figs.  1-3, 

1969.    Structural    Characteristics    of   Succineid 

Gastropod  Oxyloma  sanibelensis.  The  Nautiliix  82(3):  77-83, 
tables  1-3,  figs.  1-2. 

.  1971.  Anatomy  and  Geographic  Distribution  of 

the  Succineid  Gastropod  Suvcinea  vaginajcontorta  Lee.  The 
Nautilus  84(4):  131-142,  tables  1-2,  figs.  1-3. 

.  1973.  Oxylnma  deprimida,  A  New  Species  of  Suc- 

cineidae  (Pulmonata).  The  Nautilvs  87(3):  66-71.  tables  1-3, 
figs.  1-a 

Hubricht,  Leslie.  1961.  Eight  New  Species  of  Land  Snails  from 
the  Southern  United  States.  The  Nautilus  75(1):  26-33,  pi.  4, 
fig.  1;  75(2):  60-61,  fig.  2. 

Patters(3n,  C.  M.  1971.  Taxonomic  Studies  of  the  Land  Snail 
Family  Succineidae.  Malacological  Review  4(2):  131-202. 
tables  1-2,  figs.  1-140. 

Pilsbry.  Henry  A.  1948.  Land  Mollusca  of  North  America 
(North  of  Mexico).  Acad.  Nat.  Sci.  Philadelphia  Monograph 
3,  vol.  2.  pt.  2:  pp.i-xlvii  -I-  521-1113,  .585  figs. 

Quick,  H.  E.  1933.  The  Anatomy  of  British  Succineae.  Pmc. 
Mai.  Soc.  London  20(6):  295-318,  pis.  23-25,  tables  1-5,  figs. 


Billy  G.  Isom',  Sally  D.  Dennis^  and  Charles  Gooch' 

Lithasia  verrucosa  (Rafinesque,  1820),  Lithasia 
geniculata  salehrosa  (Conrad,  1834),  and 
Pleurocera  alveare  (Conrad,  1854)  were 
rediscovered  in  May  1977  at  Muscle  Shoals,  Ala- 
bama, below  Wilson  and  Wheeler  Dams  on  the 
Tennessee  River. 

The  last  records  of  L.  g.  salehrosa  from  the 

'Tennessee  Valley  Authority,  E&D  Building,  Muscle  Shoals. 
Alabama  35660 

'Tennessee  Valley  Authority,  Forestry  Building,  Norris,  Ten- 
nessee 37828 

Tennessee  River,  of  which  the  authors  are  aware, 
was  reported  by  Goodrich  (1934).  Davis  (1974)  and 
Stein  (1976)  presumed  that  "pure  salehrosa  is 
probably  extinct."  However,  their  statements 
were  apparently  based  on  the  literature  and  on 
material  collected  from  the  Duck  River,  but 
neither  attempted  to  sample  the  original  Ten- 
nessee River  habitat  of  this  species.  L.  g. 
salehrosa  was  found  in  the  tailwater  of  Wilson 
Dam,  the  area  from  which  Conrad  collected  the 
type  specimens. 

70      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

Ij.  veri-iicond  was  found  in  the  Tennessee  River 
at  Florence,  Alabama,  along  the  south  shore  be- 
low U.S.  Highway  72  bridge.  It  undoubtedly  oc- 
curs elsewhere  in  the  river,  but  its  total  distribu- 
tion is  not  now  known.  Historically,  this  species 
was  found  in  large  rivers  and  large  tributaries 
such  as  the  Ohio,  Tennessee,  Wabash;  Black,  and 
Spring  Rivers  in  Arkansas  (Grwdrich,  1940);  Cy- 
press and  Flint  River  tributaries  of  the  Tennessee 
River  in  Alabama;  the  Nolichucky  River  in  Ten- 
nessee (Davis,  1974);  and  other  streams.  Sinclair 
(1969)  indicated  that  L.  verrucosa  was  limited  to 
areas  below  Kentucky  and  Pickwick  Dams  in  the 
Tennessee  River. 

P.  alveare  was  found  just  below  Wheeler  Dam 
on  limestone  bluff  outcrops,  generally  in  water  to 
three  meters  deep.  Sinclair  (1969)  assumed  this 
species  was  killed  off  by  impoundment,  while 
Stein  (1976)  indicated  that  status  of  "other" 
populations  was  unknown.  Historically  this  spe- 
cies was  limited,  in  the  Tennessee  River,  to  the 
shoals  near  Florence,  Alabama,  and  to  a  number 
of  local  tributaries,  particularly  Cypress  Creek 
(Goodrich.  1934a,  1934b,  1940,  1941). 

These  snails  were  collected  by  scuba  divers. 
Collection  by  scuba  divers  is  a  very  effective 
technique  for  sampling  rock-y  substrates,  which 

are  difficult  to  sample  effectively  with  conven- 
tional grab  samplers.  We  expect  to  devehjp  addi- 
tional data  on  these  species  through  the  coming 
months.  We  particularly  wish  to  thank  W.  Jef- 
frey Pardue  and  Jimmy  G.  Walden  for  their  par- 
ticipation in  this  project. 


Davis,  George  M..  1974.  Report  on  the  Rare  and  Endangered 
Status  of  a  Selected  Number  of  Freshwater  Gastropoda 
from  Southeastern  U.S.A.  For  the  U.  S.  Department  of  the 
Interior,  Fish  and  Wildlife  Service,  Contract  No. 
M018-f)()(l8-766.  pp.  32-a5. 

Goodrich,  ("alvin,  1934a.  Studies  of  the  Gastropcxi  Famil.v 
Pleuroceridae-I.  C)rr.  Paper.'^.  Museum  of  Zoology,  University 
of  Michigan.  No.  286:  17  pages.  1  plate. 

.     1934b.     Study     of     the     Gastropod     Family 

Pleuroceridae-III.  Occ.  Papers.  Museum  of  Zoology.  Univer- 
sity of  Michigan.  No.  .300:  11  pages. 

.    1940.    The    Pleuroceridae    of   the    Ohio    River 

Drainage  System.  Occ.  Papers.  Museum  of  Zoology.  Univer- 
sity of  Michigan.  No.  417:  21  pages. 

.     1941.     Studies     of     the     GastroiX)d     Family 

Pleuroceridae-VIII.  Or.  Papers,  Museum  of  Zoology, 
l.'niversity  of  Michigan.  No.  4-17:  13  pages. 

Sinclair.  Ralph  M..  1969.  The  Pleunx^erid  Fauna  of  the  Ten- 
nessee River  Gastropoda:  Prosobranchia.  American 
Malacningical  Union,  Annual  Report:  pp.  4.5-47. 

Stein.  Carol  B.,  1976.  Gastropods.  In:  Endangered  and 
Threatened  Plants  and  Animals  of  Alabama.  Bull.  Alalmmn 
Miiseuni  <if  Natural  Hittury.  No.  2,  pp.  21-.52. 


Amy  Shrader  Van  Devender 

Mollusk  Division,  Museum  of  Zoology 

University  of  Michigan 

Ann  Arbor,  Michigan  48109 


A  new  s-pecien  of  pupillid.  Vertigo  meramecensis,  (.s  described  from  Cniwford 
County.  Mii^xonri.  It  is  most  similar  to  Vertigo  gouldi  and  in  the  sixth  Recent 
Vertigo  reported  from  the  Noiihern  Ozark  Plateau.  The  type  locality  along  Huz- 
zah  Creek  would  be  flooded  periodically  if  the  proposed  dam  on  the  Meramex: 
River  is  completed. 

On  12  June  1976  five  other  people  and  I  were 
exploring  some  wooded  limestone  bluffs  in  Craw- 
ford County,  Missouri.  The  site  was  south  of  Huz- 

zjih  Creek,  a  few  miles  south  of  where  it  joins 
Courtois  Creek  which  flows  into  the  Meramec 
River  nearby.  This  area  lies  at  the  northern  edge 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILI'S      71 

of  the  Ozarkian  Uplift  (or  Ozark  Mountains),  a 
large  plateau  covering  parts  of  four  states.  A 
representative  collection  of  land  snails,  including 
a  new  species  of  VeHigu.  was  made  just  after 
dark.  The  evening  was  warm  and  muggy;  and 
snails  were  rommon,  actively  browsing  in  the 
plant  cover  on  the  bluff  face.  The  tiny  Vetiiya. 
found  alive,  was  first  seen  by  Meg  LaVal,  who 
was  using  a  headlamp  to  search  the  mosses  and 
lichens  on  the  limestone  bluff. 

Malacologists  have  long  found  the  Ozarks  to 
contain  an  interesting  and  diverse  snail  fauna. 
As  the  literature  survey  in  Reeder  and  Miles 
(1976)  points  out,  though,  collecting  has  been 
spotty  with  only  a  few  areas  at  all  well  known.  It 
is  not  surprising  to  note  that  since  Pilsbrj'  (1948), 
only  Hubricht  (1964,  1972)  mentions  any  Voiiyo 
from  southern  Missouri. 

Vertigo  meramecensis,  n.  sp. 

Figs.  la,b:  3b 

Description  of  Holotype:  Shell  (Fig.  la)  oblong, 
tapering  with  five  well-rounded  whorls,  per- 
forate: 1.86  mm  long  and  1.15  mm  wide,  H/D  = 
1.82.  Shell  surface  (especially  middle  whorls) 
strongly,  but  irregularly  striate  with  embiyonic 
whorls  smooth.  Shell  translucent,  chestnut  in 
color;  lip  darker  than  shell  and  reflexed  with  on- 
ly a  slight  constriction.  Penultimate  whorl  bears 
a  crest  (Fig.  lb)  which  separates  the  lip  from  a 
broad  depression  external  to  the  palatal  teeth 
and  extends  to  just  above  the  middle  of  the 
whorl.  Aperture  (Fig.  3b)  one  third  shell  length, 
angular,  slightly  higher  than  wide.  Tooth  formula 
1-2-2;  subcolumellar  weakly  developed;  all  teeth, 
white,  situated  near  the  lip  edge  with  lower 
palatal  slightly  more  recessed  than  the  upper; 
parietal  in  line  with  the  lower  palatal. 

Paratypes:  Sixteen  specimens.  Adults  (n  =  10) 
have  a  reflexed  lip  and  range  in  length  from  1.72 
mm  to  2.01  mm  (x  =  1.83  ±  0.01)  and  in  width 
from  1.05  mm  to  1.20  mm  (x  =  1.10  ±  0.01).  Half 
of  the  adults  lack  a  subcolumellar  lamella 
altogether.  The  lower  palatal  is  more  recessed 
from  the  lip  edge  and  longer  than  the  upper 
palatal.  The  lower  palatal  is  variable  in  length; 
three  specimens  have  the  long,  slightly  cun-ed 
lower  palatal  shown  in  Fig.  3b  while  the  fold  is 
knob-like  in  the  holot>i)e.  This  character  may  de- 
pend on  the  maturity  of  the  animals. 

FKl.  la.  Vertigo  meramecensis  Van  Devender,  new  species. 
Hnti,t>fi>e  lUMMZ  2i7l>iO).  1.86  mm.  Crawford  Co..  Missouri. 
b,  Paratiipe  (L'MMZ2i76il).  1.87mm. 

Etymology:  From  the  Meramec  River  drainage 
where  the  species  was  collected  and  the  proposed 
Meramec  Dam  which  would  periodically  flood  the 
tyije  locality  {pers.  comm.  Dr.  R.  K.  LaVal, 
Missouri  Department  of  Conservation ). 

Types:  Holot^^pe,  Museum  of  Zoology,  Univer- 
sity of  Michigan  247640;  13  paratypes  in  the 
Museum  of  Zoology,  University  of  Michigan 
247641;  2  in  the  Field  Museum  of  Natural  His- 
tory and  the  collection  of  the  author. 

Type  Locality:  Wooded  limestone  bluffs  above 
Huzzah  Creek,  13.8  km  E  of  Steelville,  Crawford 
Countv,  Missouri  (USGS  Berrvman  15'  NWSW- 
SWNWNE  Sec  24,  T38N.  R3W). 

Discussion:  Vertigo  memmecenfns  belongs  in 
the  genus  VeHigo  because  of  its  small  size,  red- 
brown  color,  and  moderately  well-developed  teeth. 
Pilsbry  (1948:  943-1000)  discussed  the  shell  char- 
acters of  Vertigo  and  placed  most  species  in  the 
subgenus  Vertigo  (sensu  stricto).  He  divided  the 
subgenus  into  seven  species  groups  whose  compo- 
nent species  var>'  so  widely  and  overlap  so  great- 
ly that  Pilsbry  himself  was  unable  to  construct  a 
key  to  them.  The  new  species  shares  some  charac- 
ters with  at  least  two  species  groups,  the  Vertigo 
modesta  group  and  the  Vertigo  gouldi  group,  but 
seems  closest  to  the  Vertigo  gouldi  group.  Pilsbry 
(1948)  and  Hubricht  (1964,  1972)  report  eight  spe- 
cies of  Ve^iigo  from  the  northern  Ozarks.  Of 
these,  two  are  placed  in  the  Vertigo  gnuldi 
species  group  -  V.  gouldi  gouldi  and  V.  hubrichti. 
which  was  described  as  a  subspecies  of  V.  gouldi 
and  is  known  only  from  fossil  material. 

72      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

FI(_;.  :ia,  N'ertigo  ijjuldi  gduldi  (Hitmen).  (i'MMZ  mil)-  1.9 
ruin.  CuinbcrUuid  Co..  Maine,  b.  Vertigo  hubrichti  Pikhry. 
Paratmw  (ANSiP  m)S(>2).  2.0.J  mm.  St.  Lmm  O,..  Mi^simri. 

Vertigo  meramecensis  resembles  the  species 
and  subspecies  in  the  V.  gouldi  group  in  that  it 
has  a  distinctly  striate  shell,  averages  less  than  2 
mm  long  and  displays  about  5  moderately  well- 
developed,  white  teeth.  Unlike  the  majority  of 
members  in  the  species  group,  it  lacks  an  angular 
lamella  and  its  parietal  lamella  is  directly  in  line 
with  the  lower  palatal  fold. 

Comparisons  with  the  Ozarkian  members  of  the 
V.  gouldi  group  are  in  order.  Vertigo  meramecen- 
nis  at  least  superficially  resembles  the  illustra- 
tion in  Pilsbry  (1948:973,  Fig.  521)  of  the  fossil  V. 
hubrichti.  E.xjimination  of  four  paratypes  of  Ver- 
tigo gouldi  hubrichti  (ANSP  160362,  Fig.  2b), 
however,  shows  that  V.  mprnmprrnsin  has  a 
smaller,  more  tapered  and  more  distinctly  striate 
shell.  While  the  lower  palatal  fold  of  V.  hubrichti 
(Fig.  3a)  is  situated  very  deeply  in  the  mouth  of 
the    shell    like     V.    gouldi    pamdoxa    and     V. 

nijliinderi,  the  palatals  of  V.  mpramecentfis  (Fig. 
3h)  are  close  to  the  lip  edge  with  lower  fold  only 
slightly  more  recessed  than  the  upper.  The  parie- 
tal of  V.  hubrichti  points  toward  the  upper 
rather  than  the  lower  palatal  fold.  The  sculpture 
of  Vertigo  meramecensis  is  heavier  and  more  ir- 
regular than  in  Vertigo  gouldi  gouldi  (Fig.  2a) 
and  V.  meramecensis  with  smaller  teeth  has  a 
more  open  aperture  than  V.  gouldi.  The  parietal 
tooth  especially  is  less  massive  and  straighter 
than  in  V.  gouldi  (Fig.  3c)  whose  parietal  points 
between  its  palatal  folds. 

Of  the  Vertigo  species  known  from  outside  the 
Ozarks,  V.  meramecensis  most  closely  resembles 
the  illustrations  of  Vertigo  gouldi  cristata  from 
Eastern  Canada  (Pilsbry  1948:967-4,5).  Compar- 
isons with  a  series  of  shells  from  Southern  On- 
tario (UMMZ  180213)  show  that  V.  meramecenda 
has  heavier  teeth,  a  more  nearly  square  aperture, 
a  darker  (redder)  color  and  a  weaker  crest  than 
cristata.  Vertigo  meramecensis  sometimes  has  the 
subcolumellar  (basal)  lamella  that  never  occurs  in 
V.  g.  cristota. 

Land  snails  collected  with  Vertigo  meramecen- 
sis include  Anguispira  alternata  (1),  Glphi/alinia 
iudentata  (2),  Mesodon  thyroidus  (1).  Mcsodou 
zaletiis  (18),  Triodopsis  fosteri  (39),  and  Triodop- 
•s/.s-  albolabns  (5). 


The  scanning  electron  micrographs  were  taken 
by  the  author  with  the  help  and  advice  from  the 
staff  of  the  SEM  Laboratory,  Department  of 
Metallurgy  and  Dr.  Alex  Tompa,  Museum  of 
Zoology,  University  of  Michigan.  Dr.  Tompa  and 

FIG.  :?a,  Verlifci)  hubrichti  PilKhrii.  Pmatinx'  IA.\'SP  lno.UiJ). 
Enlanjnuent  of  aperture,  r.  l.^.i  X.  b.  Vertigo  meramecensis 
Win  I  )e  re  litter,  neie  xperiex.  Parat  iflte  fl'MMZ  i.',7l>ill.  Aper- 

ture irith  siiheiiliiiKellar  ItiiiieUiu  e.  lJ,.'i  X.  c,  Vertigo  gouldi 
gouldi  (Binneij)  (i'MMZ  iJ.iJlJ.  Enlargement  of  aperture,  e. 
l.',r,  X. 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      73 

Dr.  J.  B.  Burch  (l)oth  UMMZ)  and  Dr.  Georpe  M. 
Davis  (ANSP)  kindly  let  me  e.xamine  and  take 
micrographs  of  material  in  their  care.  I  want  to 
thank  Mep  and  Richard  LaVal  and  Richard  W. 
Fullington  who  read  early  drafts  of  the  manu- 
script. Special  thanks  to  R.  W.  Van  Devender, 
Leslie  Hubricht.  and  J.  B.  Burch  who  each  in  his 
ow-n  way  encouraged  me  to  wi-ite  this  paper. 


Hubricht.  Leslie.  1964.  Some  Plei.sti>cene  Land  Snail  Records 

from  Missouri  and  Illinois. S^fWi-iV/zja.  (13):  7-17. 
1972.     Land    Snail     Reairds    from     Missouri. 

Sterkiana,  (45):  34-^5. 
Pilsbn',  Henry  A.   1948.   Land   Mollusca  of  North  America 

(North  of  Mexico).  Mimdyniph  Aiwl.  \ul.  Sri.  Philadelphia 

3. 2(2):  868-1018. 
Reeder.  Richard  L.  and  Charles  D.  Miles.  1976.  Land  Snails 

from  Northern  Missouri. SferWano,  (61):  15-18. 




Alton  C.  Boozer  and  P.  E.  Mirkes 

Department  of  Environmental  Science,  School  of  Public  Health 

Belle  W.  Baruch  Institute  for  Marine  Biologv'  and 

Coastal  Research,  and  The  Department  of  Biology 

University  of  South  Carolina 

Columbia,  South  Carolina  29208 

In  the  cooling  water  system  at  the  ERDA  Savannah  River  Plant,  the  introduced 
Asiatic  clam,  Corbicula  fluminea,  is  inhabiting  the  floor  of  the  sedimentation  basin 
and  is  contributing  to  fouling  problems.  A  second  species  of  bivalves,  the  fing email 
clam,  Musculium  partumeium,  permanently  inhabits  the  wall  of  the  basin  by 
means  of  a  byssal-like  attachment.  The  possibility  of  spatial  competition  between 
these  two  bivalves  is  discussed  with  emphasis  on  ok^ervations  on  reproduction.  It 
is  concluded  that  because  of  physiological  adaptability  M.  partumeium  can  coexist 
with  Corbicula. 

The  Asiatic  clam,  Corbicula  fluminea  (Muller)', 
was  first  reported  in  the  United  States  in  1938  in 
the  Columbia  River  of  Washington  State  (Ingram, 
1959).  By  1963,  Corbicula  had  spread  into  the 
Mississippi  and  Gulf  of  Mexico  Drainage,  as  evi- 
denced by  the  Ohio  River  and  Tennessee  River 
discoveries  (Sinclair  and  Ingram,  1961;  Keup  et 
ai.  1963).  Sinclair  (1971)  excluded  the  Atlantic 
Slope  region  from  the  known  range  of  Corbicula 
until  Sickel  (1973)  reported  that  the  exotic  clam 

'  This  species  is  called  Corbicula  manilensis  Philippi  by  many 
workers,  but  we  prefer  to  use  the  earlier  name,  fluminea 

had  probably  been  introduced  to  the  Altamaha 
River  of  the  Southern  Atlantic  Slope  region  of 
Georgia  in  1968  or  1969.  Fuller  and  Powell  (1973) 
reported  Corbieida  in  the  Savannah  River  and 
Delaware  River.  Diaz  (1974)  found  Corbicula  in 
the  James  River,  Virginia,  and  more  recently, 
Rodgers  et  al.,  (1977)  reported  Corbicula  in  the 
New  River,  Virginia. 

During  the  course  of  its  range  extension,  Cor- 
bicula has  caused  a  dramatic  increase  in  water 
use  interference.  Ingram  (1959)  reported  Cor- 
bicula   fouling   problems   in    California,   as   did 


April  23. 1979 

Vol.  93  (2-3) 

Sinclair  (1964)  in  Tennessee.  After  the  introduc- 
tion of  Corbicula  in  the  Savannah  River,  a 
similar  fouling  problem  developed  at  the  United 
States  Energy  Research  and  Development  Ad- 
ministration's (ERDA)  Savannah  River  Plant. 
Openings  in  a  plate  from  a  non-reactor  cooling 
process  were  clogged  with  adult  Corbicula  shells, 
thus  restricting  water  flow  (Tilly,  1976;  pergonal 

Fouling  caused  by  the  Corbicula  invasion  is  not 
the  only  concern  of  investigators.  The  possibility 
of  a  drastic  impact  on  other  bivalves  has  been  of 
great  concern  to  biologists.  Sickel  (1973)  observed 
that  where  Corbicula  were  most  dense  in  the 
Altamaha  River,  Georgia,  there  were  no  union  ids, 
although  the  habitat  appeared  suitable.  Gardner 
et  al.  (1976)  determined  that  the  invasion  of  Cor- 
bicula in  the  Altamaha  River  had  been  ac- 
companied by  a  drastic  decline  in  the  populations 
of  other  bivalves  (Pisidiidae  and  some  Union- 

During  Ccrrbicula  fouling  studies  at  the  ERDA 
Savannah  River  Plant,  a  sedimentation  basin  of  a 
water  treatment  plant  was  found  to  contain  two 
dominant  species  of  bivalves.  One  of  the  species 
was  Corbicula  fluminea  (Miiller),  the  other 
species  was  Musculium  partumeium  (Say). 
Earlier  studies  had  shown  that  the  Corbicula  in- 
vasion had  had  an  impact  upon  other  bivalves. 
This  study  deals  with  the  association  between  M. 
partumeium  and  Corbicula. 

Description  of  Study  Area 

The  study  area  is  located  within  the  designated 
4(X)  area  of  the  U.S.  Energy  Research  and 
Development  Administration's  (ERDA)  Savannah 
River  Plant.  A  water  intake  structure  is  located 
on  the  Savannah  River  from  which  water  is 
pumped  through  a  closed  pipe  to  the  400  area 
water  treatment  plant.  Water  is  first  received  at 
the  plant  in  a  sedimentation  basin.  From  this 
point,  a  portion  of  the  water  receives  additional 
treatment  for  extensive  use  in  the  400  area.  The 
larger  portion  of  incoming  water  receives  little 
treatment  and  is  used  as  cooling  water  in  a  non- 
reactor  cooling  process.  It  was  in  this  cooling  pro- 
cess that  Corbicula  fouling  was  first  observed.  A 
subsequent   investigation   lead   to   the   discovery 

that  the  sedimentation  basin  had  become  a  per- 
manent habitat  for  freshwater  clam  populations 
of  both  Corbicula  and  M.  partumeium. 

The  sedimentation  basin  consists  of  concrete 
bottom  and  walls.  The  bottom  of  the  basin  is 
covered  with  an  extensive  amount  of  mud,  silt, 
and  sand  from  the  settling  process.  Due  to  the 
sediment  buildup,  the  depth  of  the  basin  ranges 
from  4  to  8  feet  with  an  average  depth  of  5  feet. 
An  excellent  substrate  has  developed  for  macro- 
invertebrates,  since  the  basin  has  not  been 
cleaned  in  at  least  eight  years.  Water  remains  at 
a  fixed  level  in  the  basin  throughout  the  year, 
thus  allowing  some  organisms  to  inhabit  the  con- 
crete walls  of  the  basin.  It  was  decided  that  since 
fouling  problems  had  originated  in  the  sedimen- 
tation basin,  specimens  would  be  collected  from 
that  area. 

Additional  sampling  was  attempted  in  the 
Savannah  River  adjacent  to  the  Savannah  River 
Plant  property.  Water  fluctuation  resulting  from 
the  Clark  Hill  Reservoir  Hydroelectric  Plant 
made  river  access  difficult,  and  therefore  sam- 
pling was  abandoned. 

Materials  and  Methods 

Qualitative  samples  were  taken  monthly  from 
the  400  area  sedimentation  basin  from  January, 
1976,  through  July,  1976,  including  a  semi-monthly 
sample  in  June,  1976.  Samples  of  Corbicula  were 
obtained  by  scooping  the  clams  from  the  bottom  of 
the  basin  with  a  commercial  clam  shovel.  Samples 
were  collected  from  the  walls  of  the  basin  with  a 
plankton  net  (25  micron).  The  net  was  lowered  to 
the  substrate-water  interface  beside  the  wall  and 
then  dravTO  up  the  side  of  the  wall  toward  the 
water  surface.  An  effort  was  made  to  take  approx- 
imately the  same  amount  of  material  each  time 
since  careful  quantitative  measurement  was  not 
possible.  Samples  were  placed  in  styrofoam  coolers 
containing  aerated  river  water  and  returned  to  the 
laboratory  for  careful  sorting  so  that  the  young 
would  not  be  overlooked. 

Numerous  gross  dissections  were  made  under  a 
binocular  scope  and  many  observations  were  made 
upon  young  and  transparent  specimens  under  a 
compound  microscope.  A  sub-sample  of  30  of  the 
fingernail  clams,  M.  partumeium.  was  taken  from 
each  of  the  April,  May  and  June  collections  for 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      75 

determination  of  approximate  brood  sizes  for  iden- 
tification purposes.  The  left  and  right  inner 
demibranches  of  the  gills  were  excised  from  each 
parent,  and  enclosed  larvae  were  counted  and 
measured  for  length  with  the  aid  of  an  ocular 
micrometer.  Unfortunately,  because  of  the  nature 
of  the  collecting  method  employed,  it  was  impossi- 
ble to  determine  whether  some  or  all  of  the  extra- 
marsupial  larvae  had  been  prematurely  born  or 
aborted,  with  the  result  that  the  number  of  in- 
cubating larvae  found  upon  dissection  may  have 
been  misleadingly  low.  Determinations  were  made 
to  approximate  size  classes  for  developmental 
stages  of  M  partumeium  larvae. 

During  August,  1976  the  study  was  abruptly 
halted  when  collections  indicated  that  a  complete 
kill  of  both  species  of  clams  had  occurred.  Post- 
chlorination  facilities  at  the  water  treatment  plant 
had  become  inoperable,  leading  to  emergency  pre- 
chlorination of  water  prior  to  its  entry  in  the 
sedimentation  basin.  Malfunction  of  the  pre- 
chlorination equipment  allowed  excessive  levels  of 
chlorine  to  enter  the  basin  for  a  period  of  several 
days,  thus  resulting  in  the  kill. 

A  collection  of  Corbicula  was  made  in  the  Savan- 
nah River  on  August  26, 1976  to  check  for  gravidity. 
An  attempt  was  made  to  collect  M.  partumeium. 
but  none  were  found.  Since  Corbicula  in  the  Savan- 
nah River  were  incubating  young,  qualitative  and 
quantitative  samples  were  collected  from  the 
sedimentation  basin  in  January  and  April,  1977,  to 
determine  if  repopulation  was  occurring  through 
recruitment  from  the  Savannah  River.  The  quali- 
tative samples  were  collected  from  the  wall  of  the 
basin  as  described  previously.  Quantitative 
samples  of  the  bottom  material  were  made  with  a 
standard  Ekman  dredge.  All  of  these  collections 
were  preserved  immediately  in  70  percent  ethanol 
and  returned  to  the  laboratory.  Clams  were  iden- 
tified and  counted,  and  some  sf)ecimens  were  mea- 
sured for  length  (anterior  to  posterior)  with  an 
ocular  micrometer. 

Results  and  Discussion 


The  superfamily  Corbiculacea  Gray,  1847  is 
represented  in  North  America  by  37  species  of  the 
family  Pisidiidae  Gray,  1857  (formerly  Sphaeri- 
idae,  Jeffreys,  1862),  and  by  one  introduced  species 

(Corbicula  fluminea)  of  the  cosmopolitan  family 
{x)rbiculidae  (Burch,  1975).  The  Pisidiidae  contain 
the  five  genera  Sphaerium,  Musculium,  Pmdium, 
Byssanodonta,  and  Eupera.  Baker  (1927)  divided 
the  family  into  two  subfamilies,  based  on  the  char- 
acters of  the  siphons.  Heard  (1965)  later  found 
enough  differences  to  warrant  three  separate  sub- 
families, distinguishable  on  the  basis  of  the  nature 
of  their  siphonal  arrangement  and  development  of 
their  embryos.  The  subfamilies  are  Sphaeninae, 
containing  the  genera  Sphaerium  and  Musculium.; 
Pisidiinae.  containing  the  genus  Pisidium;  and 
Euperinae.  containing  the  genus  Eupera  (Burch, 

In  North  America  there  are  eight  species  of 
Sphaerium  and  four  species  of  Musculium  (Burch, 
1975).  One  of  the  characteristics  used  to  justify  the 
validity  of  Musculium  as  a  genus  was  the  presence 
of  a  calyculus  or  "cap"  at  the  umbone.  Sterki  (1909) 
found,  however,  that  in  most  species  of  Musculium. 
specimens  are  found  with  slightly  or  noncalyculate 
beaks  and  that  calyculate  beaks  are  found  occa- 
sionally in  specimens  of  Pisidium  and  Sphaerium. 
Herrington  (1962)  suggested  that  calyculi  have  lit- 
tle taxonomic  value  because  he,  too,  witnessed  their 
occurrence  in  groups  other  than  Musculium.  He 
concluded  Musculium  to  be  a  synonym,  or  at  most  a 
subgenus,  of  Sphaerium  because  of  the  lack  of 
significant  diagnostic  shell  characteristics  to  dis- 
tinguish the  two.  When  Gale  (1972)  determined 
that  arrested  growth  caused  the  formation  of  a 
calyculus,  he  further  questioned  the  taxonomic  im- 
portance of  this  character.  Studies  on  calyculate 
and  uncalyculate  forms  of  Mu.sculium  securis 
(Prime)  by  Mackie  and  Qadri  (1974)  indicated  that 
calyculism  is  a  predictable  feature,  and  that  the 
so-called  "caps"  of  Sphaerium  species  are  probably 
"pseudocalyculae".  True  calyculae  are  separated 
from  adult  valves  by  a  sulcus,  but  "pseudocaly- 
culae" are  separated  by  an  annulus.  The  calyculate 
character  is  of  significance  in  identifying  different 
generations  in  Musculium  populations. 

More  recently.  Heard  (1977)  has  indicated  that 
Musculium  is  a  valid  genus  on  the  basis  of  several 
life  history  aspects.  He  concluded  that:  (1)  propor- 
tionately more  species  of  Musculium  can  inhabit 
temporary  ponds  than  species  of  Sphaerium;  (2)  the 
extra-marsupial  larvae  of  all  knovra  species  lack 

76      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

eggs  and  sperm,  which  are  found  in  the  larvae  in 
most  species  of  Sphaerium;  (3)  all  known  species  of 
this  group  show  a  higher  fecundity,  in  terms  of  to- 
tal numbers  of  young  produced,  than  do  most  spe- 
cies of  Sphaerium:  (4)  its  species  in  general  appear 
to  have  a  shorter  life  cycle  (30-70  days)  than  do 
Sphaerium  spp.  (4-8  months);  (5)  individuals  of  this 
group  may  have  a  shorter  life  span  than  do  those  of 
most  species  of  Sphaerium:  and  (6)  the  two  siphons 
in  Musculium  are  fused  together  in  their  basal 
halves  only,  whereas,  those  in  Sphaerium  are  fused 
together  for  their  entire  length.  In  addition,  the 
shelled  larvae  in  the  gills  of  all  Musculium  species 
and  Sphaerium  comeum  and  Sphaerium  occiden- 
tale  are  anchored  by  a  byssal  thread  to  a  common 
stalk.  Heard  (1977)  further  noted  that  S  comeum 
and  S.  occidentale  occupy  a  comparatively  in- 
termediate position  between  the  two  genera,  shar- 
ing a  number  of  features  of  both  groups  (see  Table 
1).  These  two  species  have  traditionally  been  placed 
in  Sphaerium,  either  because  of  their  lack  of 
calyculated  beaks  or  because  of  the  degree  of  siphon 

From   observations   on    anatomy,   e.xpected 
habitat,  and  life  histor\'  of  the  pisidiids.  and  up<in 
comparison  with  features  presented  in  Table  1  and 
the  preceding  discussion,  the  clam  inhabiting  the 
sedimentation  basin  was  determined  to  be  of  the 
genus  Musadium.   Although   characters  of  soft 
anatomy  are  used  in  taxonomy  of  the  Corbiculacea, 
especially    in   the   classification    to   the   generic 
level,  all  taxa  can  be  identified  by  characters  of 
the  shells,  and  such  shell  characteristics  are  par- 
ticularly important  in  distinguishing  the  species 
(Burch,  1975).  Considering  characters  of  the  shell, 
habitat,  and  range,  the  pisidiid  in  this  study  was 
identified   as  Musculium   partumeium    (Say).   A 
description  of  the  key  shell  characteristics  follows: 
Hinge  of  smooth  lateral  teeth ;  beaks  of  shell 
located  centrally  or  anterior  of  center;  shell  with 
two  cardinal  teeth  in  one  valve,  and  one  in  the 
opposing  valve;  shell  sculptured  with  fine  striae; 
adult  shell  small,  less  than  8  mm  in  length; 
posterior  end  nearly  at  right  angles  to  the  dorsal 
margin ;  anterior  ventral  margin  of  shell  slopes 
upward,  but  only  slightly;  surface  glossy  (Burch, 

TABLE  1.  Comparison  o/Sphaerium  corneum.  Sphiierium  ix-ddentale.  "?/ipr  Sphaerium.  and  Masculium  (Heard.  1S7T). 


S.  corneum 

Siphon  fusion 




Standing  water 




Mature  gametes  in  extra 

marsupial  larvae 


Functional  byssus  in 

late  larvae 


Number  of  F/^   per  sac 




Size  of  newborn 




S.  corneum    S.  occidentale   Sphaerium 


F,  -  a  collective  designation  given  fur  all  incubatinp  young  regardless  of  stage  of  development. 

Vol.  93  (2-3) 

April  23, 1979 


M.  partumeium  is  distributed  throughout  the 
United  States  and  in  southern  Canada  from  New 
Brunswick  to  Saskatchewan  (Herrington,  1962).  Its 
habitat  includes  mud  bottoms  in  small  lakes, 
ponds,  and  swamps,  and  lotic  situations.  Clarke 
(1973)  also  found  its  habitat  to  include  muddy  parts 
of  large  lakes  in  the  Canadian  Interior  Basin,  as 
well  as  vernal  ponds.  Baker  (1928)  found  it  in  black 
mud  in  shallow  water  of  stable  and  temporary 

Little  will  be  included  here  concerning  the  tax- 
onomy of  Corhicula  fluminea  in  this  study.  Sinclair 
and  Isom  (1963)  have  documented  this  subject  fully 
in  an  earlier  report.  Corbicula  from  the  400  area 
sedimentation  basin  and  the  Savannah  River  was 
easily  identified  by  the  presence  of  three  cardinal 
teeth  per  valve,  the  serrated  lateral  teeth,  and  the 
ribbed  appearance  of  the  shell  (Sinclair  and  Isom, 
1963).  Corbicula  manilensis  Philippi  is  considered 
by  us  to  be  a  synonym. 

Attachment  inM.  partumeium  (Say). 

Identifications  performed  on  the  qualitative 
samples  collected  from  the  wall  of  the  400  area 
basin  during  the  January  through  June  1976  collec- 
tions, revealed  that  a  population  of  the  fingernail 
clam,  M.  partum£ium,  was  inhabiting  the  wall  of 
the  sedimentation  basin.  From  on-site  visual  ex- 
amination of  the  samples,  it  appeared  that  the 
clams  were  actually  attached  to  the  wall  and  not 
burrowed  under  the  thin  layer  of  oligochaetes  on 
the  wall.  Live  specimens,  after  being  sorted  from 
oligochaetes  and  debris  and  being  placed  in  glass 
aquaria  in  the  laboratory,  could  readily  climb  the 
vertical  walls  of  the  container  and  attach  to  the 
glass.  The  foot  of  the  clam  is  used  in  climbing  but 
once  the  clam  is  on  the  vertical  surface,  threadlike 
filaments  allow  the  clam's  valves  to  remain  closed 
while  the  clam  is  freely  suspended  from  the  side  of 
the  glass.  Shell  lengths  of  the  M.  partumeium  en- 
countered on  the  wall  and  observed  in  the  lab- 
oratory ranged  from  1.2  mm  to  6.2  mm. 

In  describing  the  subfamily  Sphaeriinae,  Monk 
(1928)  noted  that  the  foot  is  anchored  by  means  of 
an  expansion  of  the  anterior  tip  and  ventral  side. 
Adhesion  is  facilitated  by  a  mucus  secretion  from 
the  mucus  glands  of  the  foot.  He  noted  that  the 
mucus  secretion  is  an  important  means  of  anchor- 
ing the  foot,  and  that  young  specimens  could  climb 

vertical  surfaces  by  this  aid  alone.  Monk  (1928)  ad- 
ded that  the  byssal  gland  is  vestigial  in  Sphaeri- 
inae. The  gland  is  much  larger  in  the  embryo,  but 
the  duct  that  supplies  the  gland  is  already  occluded 
in  embryos  1  mm  or  less  in  length.  In  contrast, 
Baker  (1928)  stated  that  while  the  adults  usually 
bury  themselves  in  the  bottom,  the  young  may  be 
very  active,  crawling  over  plants  and  even  suspend- 
ing themselves  from  plants  by  byssal  threads,  thus 
suggesting  a  functional  byssal  gland. 

When  Heard  (1965)  divided  the  Pisidiidae  into 
three  subfamilies,  he  stated  that  Euperinae 
possess  a  functional  byssal  gland,  whereas  Sphae- 
riinae (Sphaerium  and  MusculiumJ  and  Pisidii- 
nac  did  not.  Byssanodonta.  another  pisidiid,  lim- 
ited in  distribution  to  South  America,  is  known 
to  have  a  functional  byssal  gland.  More  recently, 
Heard  (1977)  has  reported  that  a  functional 
larval  byssus  occurs  in  all  North  American 
species  of  Miisculium,  Sphaerium  ocddentale 
(Prime),  and  Sphaerium  comeum  (Linnaeus).  The 
byssus  is  evident  in  the  shelled  larvae  (prodisso- 
conch  and  extra-marsupial  development  stages) 
and  is  believed  to  function  in  the  prevention  of 
precocious  birth  (abortion)  until  the  larval  gonads 
sexually  mature  (Heard,  1977).  Mackie  et.  al, 
(1974a)  described  the  structure  of  the  larval 
byssus  of  Musculium  securis  (Prime)  as  consisting 
of  a  byssal  stalk  that  originates  in  the  foot  of  the 
prodissoconch  larvae  and  a  byssal  bulb  that  in- 
serts on  the  descending  lamella  of  the  inner  gill 
of  the  parent.  In  this  study,  dissection  of  gills  of 
M.  partumeium  collected  from  the  sedimentation 
basin  revealed  the  presence  of  the  byssal  stalk 
and  byssal  bulb  on  prodissoconch  and  some  extra- 
marsupial  larvae. 

In  reviewing  the  significance  of  the  byssus  in 
bivalves,  Yonge  (1962)  stated  that  in  cases  where 
the  byssus  is  retained  for  permanent  attachment  of 
the  adult,  it  also  functions  in  early  life  when  the 
foot  is  still  active  as  an  organ  of  temporary  attach- 
ment. By  this  means,  the  young  bivalve  climbs  ver- 
tical surfaces.  He  added  that,  in  general,  wherever 
a  functional  byssal  apparatus  is  present  it  is  ob- 
viously related  to  a  change  in  habit  from  infaunal 
to  epifaunal  life.  Yonge  (1962)  concluded  that  the 
presence   of  a   byssal    apparatus    in    the   adult 

78      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

represents  the  persistence  of  a  post-larval  organ. 
i.e.,  that  the  animals  possessing  it  are  in  this 
respect  neotenous. 

The  functional  larval  byssus,  the  epifaunal  hab- 
itat of  the  clams  on  the  basin  wall  as  well  as  the 
record  of  vertical  attachment,  all  suggest  a  func- 
tional byssus  in  adult  M.  partumeium.  Whether  the 
byssal-like  attachment  by  thread  derives  from  a 
functional  byssus  or  by  mucus  secretions  from  the 
foot  is  uncertain.  However.  M.  partumeium  does 
have  a  method  of  attachment  allowing  it  to  inhabit 
the  wall  of  a  basin  throughout  its  lifetime. 

Notes  on  Reproductum. 

During  the  course  of  this  study,  some  observa- 
tions on  reproduction  in  M.  partumeium  were 
made,  mainly  for  the  purpose  of  identification  of 
the  species  but  also  to  note  any  major  changes  in 
reproductive  habit  associated  with  byssal-like  at- 
tachment to  the  wall  of  the  sedimentation  basin. 
Observations  on  reproduction  in  Corbicula  were 

Like  all  Sphaeriinae,  M.  partumeium  is 
monoecious  and  ovoviviparous;  it  is  self-fertil- 
izing internally  (Thomas,  1959).  Fertilized  eggs 
are  retained  and  incubated  within  the  body  of 
the  parent,  and  development  of  the  embryos  takes 
place  in  the  marsupial  or  brood  sacs  formed  by 
the  inner  (anterior)  gills.  Gilmore  (1917)  and 
Mackie  et  at..  (1974b)  have  described  the  struc- 
ture and  development  of  such  brood  sacs  in  cer- 
tain species  of  Sphaeriinae.  In  his  division  of  the 
Pisidiidae  into  3  subfamilies,  Heard  (1965)  used 
as  a  distinguishing  characteristic  the  fact  that  in 
Sphaeriinae  the  embryos  develop  in  several  thin- 
walled  longitudinal  sacs  in  each  anterior  gill, 
each  sac  containing  one  or  more  embryos. 

Observations  on  samples  collected  from  the  sed- 
imentation basin  during  January  through  July, 
1976,  and  January  and  April,  1977,  revealed  that 
some  M.  partumeium  were  brooding  extra - 
marsupial  larvae  in  the  gills  during  each  collec- 
tion. A  peak  in  number  of  young  ranging  in  size 
from  1.3-2.0  mm  was  evident  in  the  June  10,  1976 
sample  and  the  January,  1976  and  1977  samples. 
All  clams  collected  were  not  size  classed,  but  the 
January  and  June  peaks  in  number  of  young 
were  visually  evident  during  field  collection  and 
laboratory  examination. 

Gilmore  (1917)  and  Foster  (1932)  reported  that 
reproduction  in  Sphaerium  goes  on  throughout 
the  year,  with  a  preponderance  of  young  at  cer- 
tain times  of  the  year.  Mackie  et  al.,  (1976a) 
found  that  births  occurred  throughout  the  year  in 
a  population  of  M.  securis  collected  from  a  per- 
manent aquatic  habitat  in  Canada.  They  con- 
cluded from  size  classes  dominating  the  summer 
collections  and  from  newborn  dominating  the 
winter  population  that  birth  periods  occurred  in 
early  summer  and  late  summer-early  autumn  in 
the  permanent  habitat.  Thomas  (1959,  1963,  1965) 
studied  a  population  of  M.  partumeium  in  a  tem- 
porary pond  and  found  that  the  production  of  the 
first  young  was  seen  in  June  when  the  pond  had 
filled  in  March.  Standing  water  disappeared  from 
the  pond  in  late  June,  leaving  primarily  young 
individuals  which  maintained  the  clam  popula- 
tion over  the  winter.  Mackie  et  al.,  (1976b)  con- 
cluded from  studies  on  M.  securis  that  in- 
trapopulation  variations  in  reproduction  are 
more  pronounced  in  temporar>'  than  in  perma- 
nent aquatic  habitats  and  that  reproductive 
habits  may  be  adaptively  modified.  Heard  (1977) 
suggested  that  fertilization  and  birth  can  occur  at 
any  time  in  an  animal,  but,  because  of  relative 
synchronization  of  individuals,  a  population  can 
display  seasonal,  peak  periods  of  those  activities. 

Dissections  of  the  inner  gills  of  adult  M.  par- 
tumeium during  this  study  revealed  that  four 
developmental  stages  of  incubating  young  (F,)  oc- 
curred. These  four  stages,  each  arising  from  a  dif- 
ferent time  of  fertilization,  have  been  described 
by  Heard  (1977)  and  Mackie  and  Huggins  (1976) 
as  follows:  embryos  which  include  all  develop- 
mental stages  between  the  zygote  and  completed 
gastrula;  fetal  larvae  which  include  all  devel- 
opmental stages  between  the  gastrula  and  the 
beginning  of  the  formation  of  the  shell;  pro- 
dissoconch  larvae  which  include  all  developmen- 
tal stages  of  shelled  larvae  while  within  brood 
sacs;  and  extra -marsupial  larvae  which  are  those 
that  have  escaped  from  the  brood  sacs  and  lie 
free  in  the  interlamellar  space  prior  to  birth  or 
are  byssally  attached  to  the  demibranch.  Figure  1 
shows  these  four  developmental  stages  in  M.  par- 
tumeium determined  by  numerous  gill  dissections 
of  adults.  General  size  distinctions  were  made 
between  F,  of  the  four  stages  of  development.  The 

Vol.  93  (2-3) 

April  23. 1979 


FIG.  1.  Life  history  o/Musculium  partumeium  (Say).  Nate  the  four 
identified asfollous:  d,  disaocnnch:  st,  statacyst:  ft, /oof,-  vm,  visceral 

specific  duration  of  incubation  of  each  of  the  four 
developmental  stages  is  unknown  for  Sphaerium 
and  Mitsculium  (Heard,  1977). 

Observations  of  dissections  of  live  specimens 
indicated  that  fetal  larvae  show  ciliary  action 
similar  to  that  shown  by  the  trochophores  of  Cor- 
bicitla.  Trochophore  and  veliger  stages  are  sup- 
pressed in  M.  partumeium,  however.  The  pro- 
dissoconch  larvae  exhibit  direct  development  with 
continued  shell  formation  until  the  visceral  mass 
is  completely  enclosed.  Internal  development 
takes  place  throughout  this  period.  The  visceral 
mass  is  moved  about  in  the  region  of  the  foot 
while  development  continues.  The  extra-mar- 
supial larvae  show  advanced  internal  structure 
similar  to  adults.  The  newly  released  clams  ap- 
pear to  be  miniatures  of  the  adult. 

The  largest  extra-marsupial  larvae  found  in 
dissections  of  M.  partumeium  were  1.40  mm. 
Heard  (1977)  found  the  largest  in  his  studies  to 
be  1.22  mm.  Thomas  (1959)  determined  a  mean 
birth  length  for  M.  partumeium  in  a  temporary 

developmental  stages  and  respective  size  classes.  Symbols  are 
mass:  g,  gills:  h,  heart. 

pond  to  be  1.6  mm,  as  compared  to  1.44  mm  in 
the  laboratory.  The  smallest  to  be  successfully 
raised  was  one  which  measured  1.25  mm  in 
length.  During  the  June  and  January  sample  col- 
lections of  this  study  when  young  production  was 
high,  the  major  size  class  ranged  from  1.3-2.1 

The  smallest  specimen  of  M.  partumeium  ex- 
amined that  contained  any  developmental  stage 
of  larvae  was  measured  at  2.58  mm  in  length.  On- 
ly embryos  were  present  in  the  brood  sac. 
Thomas  (1959)  reported  that  ovary  and  testis  are 
present  at  birth  in  M  partumeium,  but  neither 
organ  contains  mature  reproductive  cells.  The 
mean  length  of  the  newborn  was  1.6  mm,  and  the 
smallest  developing  adult  that  contained  gametes 
was  2.1  mm  long.  Mackie  et  al.,  (1976b)  found 
gametogenesis  first  apparent  in  adult  M.  securis 
of  length  2.00-2.50  mm.  They  reported  simul- 
taneous maturation  of  gametes  as  did  Thomas 
(1959)  for  M.  partumeium.  Heard  (1977)  stated 
that  extra-marsupial  larvae  of  most  Sphaerium 

80      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

already  contain  eggs  and  sperm,  whereas  gametes 
are  not  present  in  S.  occidentale  and  Musculium 
after  birth. 

Unfortunately  because  of  the  method  by  which 
samples  were  obtained,  accurate  brood  sizes  could 
not  be  determined  for  M.  partumeium.  The  true 
brood  sizes  might  have  been  larger  than  any 
found  in  this  study,  since  the  methodology  could 
have  led  to  abortion  of  extra-marsupial  larvae. 
From  general  observations,  it  was  evident  that 
brood  sizes  were  large,  with  values  ranging  from 
2  to  33.  These  data  were  considered  sufficient  for 
identification  purposes.  Gilmore  (1917)  listed  be- 
tween 10  and  20  as  the  brood  size  for  M.  par- 
tumeium, whereas  Thomas  (1959)  reported  a 
range  of  2  to  30  and  a  mean  of  10  for  the  same 
species.  Heard  (1977)  found  as  many  as  14  F,  per 
brood  sac  and  from  1  to  5  sacs  in  M.  partumeium. 
When  dissected,  older  adult  M.  partumeium  con- 
tained a  greater  number  of  F,  than  younger 
adults.  An  increase  in  generative  performance 
with  age  has  been  reported  by  Thomas  (1959)  and 
Heard  (1977)  for  M.  partumeium  and  by  Mackie 
et  a/.,  (1976b)  for  M.  securis. 

The  life  history  of  Corbicula  has  been  described 
by  Sinclair  and  Isom  (1963).  Corbicula  from  the 
Savannah  River  and  the  400  area  sedimentation 
basin  show  similar  developmental  stages.  Of  ma- 
jor importance  is  the  fact  that  Corbicula  young 
are  released  as  planktotrophic  veligers  or  benthic 
veligers  at  a  size  of  approximately  0.22  mm.  The 
importance  of  this  will  be  discussed  later. 

Samples  of  Corbicula  collected  January-July, 
1976,  from  the  sedimentation  basin  and  August 
25,  1976,  from  the  Savannah  River  were  examined 
for  gravidity.  Specimens  inspected  in  May  and 
early  June  were  incubating  veligers  in  the  gill. 
Not  until  August  25,  1976,  were  Corbicula  again 
found  to  be  gravid.  The  sample  from  the  Savan- 
nah River,  taken  adjacent  to  the  400  area  water 
intake,  showed  Corbicula  to  be  incubating 
trochophore  larvae  at  that  time. 

The  findings  of  this  study  on  the  reproductive 
period  confirm  reports  in  the  literature.  Sickel 
(1976)  examined  plankton  samples  for  Corbicula 
larvae  in  the  Altamaha  River  in  Georgia.  He 
found  larvae  present  in  the  water  column 
throughout  the  year,  except  for  the  month  of 
March,  with  a  peak  density  in  May.  Aldridge  and 

McMahon  (1976)  reported  that  Corbicula  have 
two  generations  per  year,  a  spring  reproductive 
period  extending  from  mid-April  to  late  July  and 
a  fall  reproductive  period  extending  from  late 
August  to  late  November.  They  found  Corbicula 
from  Lake  Arlington,  Texas,  with  individual  dai- 
ly fecundities  of  387.0  veligers/clam  and  319.8 
veligers/clam  for  the  spring  and  fall  reproductive 
periods,  respectively. 

Repopulation  of  the  Study  Area  Basin. 

Qualitative  samples  collected  from  the  wall  of 
the  sedimentation  basin  and  quantitative  samples 
collected  from  the  floor  of  the  basin  in  January 
and  April,  1977  were  taken  to  determine  the  ex- 
tent of  repopulation  of  the  basin  following  the 
August,  1976,  extermination.  In  January,  1977, 
the  wall  sample  indicated  that  M.  partumeium 
was  repopulating  the  basin.  The  sample  consisted 
of  619  M.  partumeium  but  also  11  Corbicula. 
Sizes  of  M.  partumeium  ranged  from  1.26  mm  to 
6.27  mm  long,  with  a  preponderance  of  1.3-2.0 
mm  long  young.  The  Corbicula  ranged  in  length 
from  1.61  mm  to  5.0  mm.  An  examination  of  the 
bottom  material  collected  during  January,  1977, 
showed  M.  partumeium  concentrations  of 
1834/m^  as  compared  to  856/m^  of  Corbicula.  More 
numerous  in  both  species  were  young  clams  in 
the  1.3-2.0  mm  length  class.  Some  specimens  of 
both  species  attained  lengths  as  great  as  8.0  mm. 

The  results  of  the  April,  1977  sample  collec- 
tions differed  dramatically  from  the  January 
findings.  A  similar  sampling  effort  was  made  in 
the  April  sample  collection  from  the  basin  wall 
as  was  made  in  the  January  collection.  Results 
showed  3277  M.  partumeium  in  the  collection  as 
compared  to  2  Corbicula.  The  Corbicula  were  2.0 
mm  and  2.1  mm  long,  while  the  M.  partumeium 
showed  a  complete  range  of  size  classes.  Ex- 
amination of  the  April  bottom  sample  revealed 
M.  partumeium  concentrations  of  1320/m^  but 
Corbicula  concentrations  had  increased  to 
8200/m^  Corbicula  ranged  in  length  from  0.87  to 
13.9  mm  with  a  large  number  of  clams  between 
1.0  mm  and  7.0  mm.  Various  sizes  of  M.  par- 
tumeium were  collected  in  the  sample,  but  the 
greatest  number  were  4.0  mm  to  6.0  mm  in 

Vol.  9.3  (2-3) 

April  23,  1979 

THE  NAUTILUS      81 

The  results  of  the  January  and  April,  1977 
sample  collections  indicated  that  repopulation  of 
the  sedimentation  basin  was  well  underway. 
Since  newly  released  M.  partumeium  are  usually 
at  least  1.25  mm  long,  it  would  seem  that  recruit- 
ment from  the  river  may  span  a  wide  distribu- 
tion of  sizes.  Results  of  the  variety  of  size  classes 
present  in  the  January  and  April,  1977  samples 
would  tend  to  support  this  belief.  In  recent  imp- 
ingement and  entrainment  studies  at  the  Savan- 
nah River  Plant,  it  has  been  determined  that  not 
only  Corbicula  veligers  but  also  benthic  larvae 
and  juveniles  are  recruited  in  the  water  intakes 
(Tilly,  1976;  personal  communication).  Corbicula 
are  well-established  in  the  Savannah  River  near 
the  study  area.  M.  partumeium  have  not  been  col- 
lected from  the  river,  although  the  vast  Savannah 
River  swamp  would  seem  to  be  an  ideal  habitat 
for  this  clam.  Lack  of  collection  has  probably 
resulted  from  the  inability  to  put  a  boat  in  the 
river  at  high  water  and  the  inaccessibility  of  the 
swamp  when  one  does  get  a  boat  in  the  river  at 
low  water. 

The  majority  of  the  younger  clams  present  in 
the  January,  1977  sample  were  probably  re- 
cruited directly  from  the  river,  although  some 
might  have  been  bom  in  the  basin  from  gravid 
clams  recruited  in  the  Fall.  M.  partumeium  up  to 
8.0  mm  in  length  were  present  in  the  January 
sample,  as  well  as  some  Corbicula  of  the  same 
size.  Sinclair  and  Isom  (1963)  found  Corbicula  to 
be  sexually  mature  at  a  length  of  6.5  mm.  Some 
reproduction  in  Corbicula  may  have  been  under- 
way by  the  time  of  the  April,  1977  collection, 
since  a  large  number  of  1.0-3.0  mm  long  clams 
were  present,  as  well  as  a  large  number  of  4.0-8.0 
mm  long  Corbicula.  M.  partumeium  appeared  to 
be  prepared  for  an  early  summer  reproductive 
period,  since  most  clams  ranged  in  size  from 
4.0-6.0  mm  long. 

Interactions  ofM.  partumeium  with  Corbicula. 

From  a  comparison  of  the  results  of  the 
January,  1977  collection  and  the  April,  1977  col- 
lections, the  number  of  Corbicula  increased 
dramatically  on  the  floor  of  the  basin  while  the 
number  of  M.  partumeium  decreased  somewhat. 
During  the  same  period  in  which  the  Corbicula 

|X)pulati()n  increased  on  the  floor  of  the  basin,  the 
population  of  M.  partumeium  increased 
dramatically  on  the  wall  of  the  basin. 

The  number  of  Corbicula  collected  from  the 
wall  of  the  basin  in  January,  1977,  was  11.  In  the 
April,  1977,  collection  from  the  wall,  when  it  ap- 
peared that  a  much  larger  population  of  M.  par- 
tumeium was  present,  only  2  Corbicula  were 
found.  During  the  January  through  July,  1976 
sample  collections,  no  Corbicula  specimens  were 
found  in  the  established  population  of  M.  par- 
tumeium on  the  wall  of  the  basin. 

M.  partumeium  and  Corbicula  are  able  to  co- 
exist in  the  basin.  The  byssal-like  attachment  of 
M  partumeium  may  give  this  species  a  com- 
petitive advantage  on  the  basin  wall.  Such  an 
adaptation  resulting  in  a  competitive  advantage 
is  supported  by  the  data  of  Heard  (1977)  which 
indicate  that  a  functional  larval  byssus  in  S.  oc- 
cidentale  and  M.  partumeium  is  an  adaptation 
for  temporary  habitats. 

Several  interactions,  such  as  food  or  space,  may 
make  it  advantageous  for  M.  partumeium  to  in- 
habit the  wall  of  the  basin  by  attachment.  Spatial 
competition  is  a  likely  possibility  considering  the 
confines  of  the  basin.  Sickel  (1973)  reported  that 
in  the  Altamaha  River,  Georgia,  no  unionids 
were  present  where  Corbicula  were  most  dense, 
although  the  habitat  appeared  suitable.  He  stated 
that  it  was  unlikely  to  be  spatial  competition 
since  the  size  of  Corbicula  and  its  density  did  not 
appear  to  be  great  enough  to  exclude  the  much 
larger  unionids.  Sickel  (1976)  later  reported  that 
Corbicula  may  be  excluding  the  juvenile  unionids 
which  may  eventually  result  in  the  loss  of  ende- 
mic species  of  clams.  This  competitive  interaction 
would  be  more  closely  representative  of  the  situa- 
tion with  M.  partumeium.  Corbicula  in  the 
sedimentation  basin  and  the  Savannah  River 
ranged  in  maximum  size  from  25  mm  to  35  mm 
long.  In  comparison,  M.  partumeium  collected 
from  the  basin  reached  a  maximum  size  of  8.0 
mm  in  length. 

There  also  may  be  spatial  competition  for  the 
wall  habitat  of  the  basin.  From  earlier  discus- 
sions, it  was  shown  that  Corbicula  were  present 
in  very  few  numbers  in  January  and  April,  1977 
sample   collections   and   not   present    at   all    in 

82      THE  NAUTILUS 

April  23,  1979 

Vol.  93  (2-3) 

Januarj'-July,  1976  sample  collections  although 
the  wall  of  the  basin  was  well  populated  with  M. 
partumeium.  Although  Corbicula  is  known  to 
have  a  functional  byssus  (Sinclair  and  Isom, 
1963).  the  size  at  which  the  clam  is  released  from 
the  gills  of  the  adult  would  place  it  at  a  definite 
disadvantage.  As  mentioned  earlier  in  the  text, 
the  veligers  of  Corbicula  measure  approximately 
0.22  mm  when  released.  In  comparison,  M.  par- 
tumeium measures  approximately  1.3  mm  in 
length  or  larger  when  released  from  the  gills 
(Figure  1)  which  would  seem  to  give  this  clam  a 
competitive  advantage  over  the  Corbicula  larvae 
for  the  wall  habitat,  in  this  case,  the  preferred 
habitat  for  M.  partumeium. 

Heard  (1977),  in  evaluating  fecundity  in  terms 
of  current  ecological  theory,  determined  that 
Musculium  and  S.  occidentale  are  "r-strategists" 
in  ephemeral  habitats,  devoting  more  energy  to 
reproduction.  In  contrast,  other  Sphaerium  and 
Pisidium  in  perennial  habitats  are  "k- 
strategists,"  expending  greater  energy  on  such 
non-reproductive  activities  as  maintenance. 

Corbicula  is  an  introduced  species  to  the 
United  States  and  shows  characteristics  of  both 
an  "r-strategist"  and  a  "k-strategist."  The  "r- 
strategies"  employed  by  Corbicula  include  early 
reproductive  maturity  and  high  fecundity.  The 
"k-strategies"  include  producing  young  that  have 
a  greater  survival  probability,  a  long  life  span, 
and  energy  for  competition.  It  appears  that  M. 
partumeium,  normally  an  "r-strategist"  in 
ephemeral  habitats,  may  exhibit  more  "k- 
strategies"  in  the  permanent  aquatic  habitat  of 
the  basin  and  thus  may  be  using  more  of  the 
available  energy  for  competition.  Heard  (1977) 
reported  that  where  Pisidium  and  Sphaerium 
both  exist  in  the  littoral  zone  of  lakes,  the  range 
of  the  "r-strategist"  Pisidium  extended  into  the 
profundal  zone,  because  of  interactions  with  the 
more  competitive  Sphaerium. 


Musculium  partumeium  has  retained  some  lar- 
val form  of  byssal-like  attachment  throughout  its 
lifetime  which  enables  it  to  inhabit  the  wall  of 
the  400  area  sedimentation  basin.  It  is  not  known 

whether  the  attachment  originates  from  a  func- 
tional byssus  or  from  mucus  secretions  of  the 

Some  interaction  or  competition  may  exist  be- 
tween M.  partumeium  and  Corbicula.  Spatial 
competition  is  considered  highly  probable  because 
of  the  size  differences  between  adult  Corbicula 
and  adult  M.  partumeium.  With  the  much  larger 
size,  adult  Corbicula  may  inhabit  the  preferred 
habitat  of  the  basin  floor.  In  a  like  manner,  M. 
partumeium  may  spatially  out-compete  young 
Corbicula  for  the  habitat  of  the  basin  wall,  since 
both  species  are  capable  of  byssal  attachment. 
Newly  released  M.  partumeium  are  much  larger 
than  the  Corbicula  veligers  and  therefore  may  oc- 
cupy the  wall  habitat,  in  this  case,  the  preferred 
habitat  for  M.  partumeium. 

Observations  on  M.  partumeium  collected  from 
the  basin  wall  did  not  reveal  any  major  changes 
in  reproductive  habits.  It  would  be  extremely  dif- 
ficult to  document  any  minor  variation  in  repro- 
ductive habits,  since  such  habits  are  adaptively 
modified  by  changes  in  environment  or  habitat. 

It  is  concluded  that  the  adaptability  of  M.  par- 
tumeium may  have  made  it  possible  for  the  clam 
to  coexist  in  the  sedimentation  basin  with  Cor- 
bicula. Those  species  capable  of  inhabiting  tem- 
f)orary  habitats  may  possess  the  adaptability 
necessary  to  withstand  the  Corbicula  invasion. 


This  research  was  supported  by  E.  I.  DuPont 
de  Nemours  and  Company,  Savannah  River 
Laboratory,  through  a  grant  awarded  to  the 
University  of  South  Carolina  School  of  Public 
Health.  This  work  was  submitted  in  partial 
fulfillment  of  the  degree  of  Masters  of  Science  in 
Public  Health. 


Aldridfje,  D.  W.  and  R.  F.  McMahon.  1976.  Population  growth 
and  reproduction  in  the  Hfe-cycle  of  Corbicula  mmiilensk 
Philippi.  As  abstracted  in  Corbicula  Newsletter,  ed.  J.  S. 
Mattice.  Oak  Ridge  National  Laboratory.  Vol.  1  (4).  1976. 

Baker,  F.  C.  1927.  On  the  division  of  the  Sphaeriidae  into  two 
subfamilies:  and  the  description  of  a  new  genus  of 
Unionidae,  with  descriptions  of  new  varieties.  American 
midland  Naturalist  10:  220-223. 

Vol.  93  (2-3) 

April  2.'^,  1979 

THE  NAUTILUS      83 

.   1928.   The  Freshwater  Mollusca  of  Wisconsin. 

Part  2.  Bull.  70,  Wis.  Geol.  and  Natural  History  Survey 

Ser.  1527:  x.x  +  507p  (p310-429). 
Burch,  J.  B.  1975.  Freshwater  Sphaeriaeean  Clams  (Mollusca: 

Pelecifiioda)  of  North  America.  Malacologicai  Publications, 

Hamburg,  Michigan. 
Clarke.  Arthur  H.  1973.  The  freshwater  molluscs  of  the  Cana- 
dian Interior  Basin.  Malacoloyia  13:  1-509. 
Diaz,  R.  J.  1974.  Asiatic  clam,  Corbicula  manilensis  (Philippi) 

in  the  tidal  James  River,  Virginia.  Chesapeake  Science  15: 

Foster.  T.  D.  1932.  Observations  on  the  life  history  of  a  finger- 
nail shell  of  the  genus  Sp/iwn'(/7n.  •/  Murph.  53:  473-497. 
Fuller,  S.  L.  H.  and  C.  E.  Powell    1973.  Range  extensions  of 

Corbimla  manilensis  (Philippi)  in  the  Atlantic  drainage  of 

the  United  States.  The  Nautilus  87(2):  59. 
Gale,   W     F.    1972.    Seasonal    variability    in    calyculism    in 

Sphaerium  transversum  (Say).  The  Nautilus  86(1):  20-22. 
Gardner,  J.  A.,  Jr.,  W.  R.  Woodall,  Jr.,  A.  A.  Staats,  Jr.,  and 

J.  F.  Napoli.  1976.  The  invasion  of  the  Asiatic  clam  (Cor- 
bicula manilensis  Philippi)  in  the  Altamaha  River,  Georgia. 

The  Nautilus  90{3):  117-125. 
Gilmore,  R.  J.  1917.  Notes  on  reproduction  and  growth  in  cer- 
tain  viviparous   mussels  of  the   family  Sphaeriidae.   The 

Nautilus  31:  16-30. 
Heard,  W.  H.  1965.  Recent  Eupera  (Pelecypoda:  Sphaeriidae) 

in  the  United  States.  American  midland  Naturalist  74(2): 

.    1977.    Reproduction    of    fingernail    clams 

(Sphaeriidae:    Sphaerium    and    Musculium).    Malacologia 

16(2):  421-455. 
Herrington,   H.   B.   1962.   A   revision   of  the  Sphaeriidae  of 

North  America  (Mollusca:  Pelecypoda).  Misc.  Pubis.  Mus. 

ZooL.  Univ.  Mich.  118: 1-74. 
Ingram,  W.   M.    1959.   Asiatic  clams  as  potential   pests   in 

California  water  supplies.  Jour.  A  WWA  51(3):  363-370. 
Keup,  L.,  W.  B.  Horning,  and  W.  M.  Ingram.  1963.  E.xtension 

of  range  of  Asiatic  clam  to  Cincinnati  reach  of  the  Ohio 

River.  The  Nautilus  77(1):  18-21. 
Mackie,  G.  L.,  and  D.  G.  Huggins.  1976.  Biological  notes  on 

Eupera  eubensis  (Bivalvia:   Sphaeriidae)  from   Kansas.  ./. 

Fish.  Res.  Board  Can.  33: 1652-1656. 
Mackie,  G.  L.,  and  S.  U.  Qadri.  1974.  Calyculism  in  Musculium 

seairis  (Pelecypoda:  Sphaeriidae)  and  its  significance.  Can. 

J.  Zool.  52:  977-980. 
Mackie,  G.  L.,  S.  U.  Qadri,  and  A.  H.  Clarke,  1974a.  Byssus 

structure  of  larval  forms  of  the  fingernail  clam,  Musculium 

securis  (Prime).  Gin.  J.  Zool.  52:  945-946. 

1974b.  Development  of  brood  s;ics  in  Musculium 

securis  Bivalvia:  Sphaeriidae.  The  Nautilus  88(4):  109-111. 
.  1976a.  Intra.specific  variations  in  growth,  birth  pe- 

riods, and  longevity  of  Muscuiium  securis  (Bivalvia:  Sphaeri- 
idae) near  Ottawa.  Canada,  Mulonihuiio  15(2):  4liV446. 
.  1976b.  Reproductive  habits  of  four  populations  of 

Musculium  securis  (Bivalvia:  Sphaeriidae)  near  Ottawa, 
Canada.  The  Nautilus  90(2):  76-86. 

Monk,  G.  R.  1928.  The  anatomy  and  life  history  of  a 
freshwater  mollusk  of  the  genus  Sphaerium.  J.  Morph.  45: 

Rodgers,  J.  H.,  Jr.,  D.  S.  Cherry,  J.  R.  Clark,  K.  L.  Dickson, 
and  J.  Cairns,  Jr.  1977.  The  invasion  of  Asiatic  clam,  Cor- 
bicula manilensis  in  the  New  River.  Virginia.  The  Nautilus 
91(2):  43-46 

Sickel,  J.  B.  1973.  A  new  record  of  Corbiada  manilensis 
(Philippi)  in  the  Southern  Atlantic  Slope  region  of  Georgia. 
The  Nautilus  87 {iy.n-\2. 

.  1976.  An  ecological  study  of  the  Asiatic  clam, 

Corbicula  manilensis  (Philippi,  1841)  in  the  Altamaha 
River,  Georgia,  with  emphasis  on  population  dynamics,  pro- 
ductivity, and  control  methods.  As  abstracted  in  Corbicula 
Newsletter,  ed.  J.  S.  Mattice,  Oak  Ridge  National 
Laboratory,  Vol.  2(1),  1977. 

Sinclair,  R.  M.  1964.  Clam  pests  in  Tennessee  water  supplies. 
Jmir  A  WWA  56(5):  592-.599. 

.    1971.    Annotated    bibliography    on    the    exotic 

bivalve  Corbiada  in  North  America,  1900-1971.  Sterkiana 
43: 11-18. 

Sinclair,  R.  M.  and  W.  M.  Ingram.  1961.  A  new  record  for  the 
Asiatic  clam  in  the  United  States,  the  Tennessee  River.  The 
Nautilus  7i{3):lU-nS. 

Sinclair,  R.  M.  and  B.  G.  Isom.  1963.  Further  studies  on  the 
introduced  Asiatic  clam  (Corbiada)  in  Tennessee.  Tennessee 
Department  of  Public  Health.  75  pp. 

Sterki,  Victor.  1909.  Some  observations  and  notes  on 
Musmdium.  The  Nautilus  ^(2):  17-19. 

Thomas,  G.  J.  1959.  Self-fertilization  and  production  of  young 
in  a  sphaeriid  clam.  The  Nautilus  72(4):  131-140. 

.  1963  Study  of  a  population  of  sphaeriid  clams  in 

a  temporary  pond.  The  Nautilus  77(2):  37-43. 

.  1965.  Growth  in  one  species  of  sphaeriid  clam. 

The  Nautilus  79(2):  41 -5i. 

Tilly,  L.  J.  1976.  Persmal  communication:  Research  super- 
visor. Savannah  River  Plant,  Aiken,  South  Carolina. 

Yonge,  C.  M.  1962.  On  the  primitive  significance  of  the  byssus 
in  the  Bivalvia  and  its  effects  in  evolution.  J.  mar.  biol. 
Ass.  r.  A'.  42: 113-12.5. 


Akibumi  Teramachi,  an  amateur  conchologist, 
artist,  and  well-known  Japanese  shell  collector 
died  in  Kyoto,  Japan,  at  the  age  of  80,  on 
December  6,  1978.  At  the  age  of  24  he  developed 
tuberculosis  and  went  to  Wakayama  Prefecture 
for  his  health.  There  he  became  an  avid  shell  col- 
lector, and  published  his  first  two  papers  on  con- 
chology  in  the  Venvs.  vol.  2,  in  1930.  Two  genera. 


Temmachia  and  Akibumia,  and  several  species  of 
moUusks  were  named  after  him,  especially  by 
Kuroda  and  Habe.  Cypraea  katsuae  was  named 
after  his  wife.  Some  of  the  types  in  his  collection 
were  sold  from  time  to  time,  and  the  holotype, 
for  instance,  of  Teramaehia  tibiaeformis  Kuroda, 
is  now  in  the  Academy  of  Natural  Sciences  of 

84      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 


Billy  G.  Isom',  Charles  Gooch',  and  Sally  D.  Dennis^ 

Several  commercial  mussel  boats  were  sighted 
on  the  Cumberland  River  in  July  1976.  A  visit 
was  made  to  the  area  on  September  1,  1976,  to 
determine  the  species  of  mussels  being  taken 
commercially.  Among  the  species  found  were 
several  specimens  of  one  that  had  been  presumed 
extinct  (Stansbery.  1970)  or  reduced  to  a  single 
river  system  (Stansbery,  1971).  The  species  was 
later  taken  live  near  Cumberland  River  at  mile 
296.8,  the  same  general  area  in  which  the  mussel 
boats  had  been  working.  This  species  is  believed 
to  be  confined  to  this  portion  of  the  Cumberland 
River  in  Tennessee. 

Lea  (1829)  described  the  species  as  "Shell  sub- 
elliptical,  inequilateral,  ventricose,  slightly 
marginate;  valves  thick;  beaks  nearly  terminal; 
cardinal  and  lateral  teeth  large,  and  double  in 
both  valves;  nacre  purple."  The  type  locality  was 
listed  by  Lea  as  Ohio  in  his  plate  8,  fig.  12. 

Dysnomia  sulcata  (Lea,  1829)  was  reported  to 
exist  in  the  Cumberland  River  by  Wilson  and 
Clark  (1914),  who  commented  on  its  distribution: 
"Although  this  species  seems  to  be  pretty  well 
distributed  along  a  considerable  stretch  of  river, 
we  obtained  only  occasional  examples  here  and 
there  along  the  shore  ...  It  can  probably  be  pro- 
cured in  large  numbers  during  low  water." 

"It  is  common  enough  to  be  pretty  well  known 
to  the  clammers,  who  call  it  'peewee'  on  account 
of  its  small  size,  or  'cat's-claw'  because  of  the 
peculiar  clawlike  structure  on  the  marsupial  ex- 
pansion of  the  female." 

Ortmann  (1925)  provided  good  locality  records 
for  I).  !iiilrata.  However,  he  considered  the  species 
an  "immigrant"  in  both  the  Cumberland  and 
Tennessee  Rivers,  its  principal  distribution 
centered  clearly  in  the  Ohio  and  Wabash  Rivers. 

Neal  and  Allen  (19(yl)  reported  finding  only 
one  sf)ecimen  during  their  study  of  the  mussels  of 

'Tenne&see  Valley  Authority.  E&D  Building,  Muscle  Shoals, 
Alabama  .^Sfifin 

'Tennessee  Valley  .Authority,  F(jrestry  Building,  Norris,  Ten- 
nessee 37828 

the  upper  Cumberland  River.  This  specimen  was 
found  at  Neeleys  Ford  near  Burkesville,  Ken- 

Stansbery  (1970)  stated  that  "Tlie  big  river  D. 
a.  mlcata  form  having  a  purple  nacre  may  be  ex- 
tinct, but  the  white-nacred  D.  .s.  perobliquioi  is 
still  occasionally  found  in  streams  tributary  to 
western  Lake  Erie  or  Lake  St.  Clair."  However, 
Stansbery  (1971)  stated  that  D.  f^ulcata  was 
reduced  to  a  single  river  system,  the  Green  River 
in  Kentucky'. 

Lack  of  recent  locality  records  for  this  species 
may  result  from  limited  amount  of  collecting  be- 
ing done  in  big  rivers,  especially  the  Cumberland 
River.  The  last  comprehensive  study  of  the  mid- 
dle and  lower  Cumberland  River  was  by  Wilson 
and  Clark  (1914). 

We  wish  to  thank  Steven  A.  Ahlstedt  for  his 
assi-stance  in  this  project. 


Lea.  Isaac,  1829  (18:5)).  Observation  on  thie  genus  L'nio 
together  with  descriptions  of  eighteen  species;  and  of  the 
genus  Sifiiiplnfiiotfi.  now  separated  from  the  family  of 
Naiades,  containing  nine  species.  Tmm.  Ainer.  Pliilim.  Six: 

Neel,  .Joe  K.  and  William  R.  .Allen.  1964.  The  mussel  fauna  of 
the  upper  Cumberland  Basin  before  its  impoundment. 
il/a/nfo/oyfVil  (.3):  427-459. 

Ortmann,  A.  E.  1925.  The  Naiad  fauna  of  the  Tennessee  River 
below  Walden  Gorge. /I »ienV««  Midi  Nat.  9(7):  :321-372. 

Stansben,',  David  H.  1970.  Eastern  Freshw^ater  Mollusks  (I) 
The  Mississippi  and  St.  Lawrence  River  Systems.  In:  Pni- 
cfciliiiyy  (if  the  Amrr.  Malaaihiyicnl  l'iu<i>i  Si/niixisiiini  on 
Rare  ami  F.ndangered  Mollush.  Ed.  by  A.  H.  Clarke,  (1968): 
p.  19. 

.  1971.  Rare  and  endangered  freshwater  mollusks 

in  Eastern  L'nited  States.  In:  Hare  and  Endangered 
Mollusks  (Naiads)  of  the  U.S.  Edited  by  Jorgensen  and 
Sharp.  Issued  by  the  U.S.  Dept  of  Interior.  Region  3:  pp. 

Wilson.  Charles  B.  and  H.  Walton  Clark.  1914.  The  Musi^els  of 
the  Cumberliuid  River  and  its  Tributaries.  Reixirt,  W.  S. 
Fish,  Conim.,  Washington.  D.C.,  No. 781. 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      85 


Terrence  M.  Gosliner 

Department  of  Zoolog>' 

University  of  New  Hampshire 

Durham,  N.  H.  03824 


.4  nin)-i)fi<>l<igirnl  fttiidy  ivm^  made  oftii.r  sperip^  of  the  geniif;  Cylichnella  Gahb.  1873. 
Cylichnella  oryza  wan  studied  anatornieaUyfor  the  first  time.  Coniparison  of  the  in- 
fomiatum  obtained  in  this  study  with  that  in  the  literature  suggests  that  Utriculastra 
Thiele,  1925,  should  he  regarded  as  a  junior  synonym  o/ Cylichnella.  C.  canaliculata 
and  C.  inculta,  while  similar  inform,  are  distinct  species.  C.  cerealis  is  nuiintained  as 
a  valid  species  while  C.  eximia  is  suppressed  as  a  junior  synonym  ofC.  culcitella. 


The  recent  works  of  Marcus  (1974,  1977),  Rud- 
man  (1971,  1973),  Bouchet  (1975)  have  dealt  ex- 
tensively with  the  comparative  morphology  of 
members  of  the  Cephalaspidea.  Many  species 
possess  shells  which  are  similar  in  form  yet  have 
dramatically  divergent  internal  morphology.  The 
systematics  of  the  Cephalaspidea  has  been  more 
clearly  defined  as  a  result  of  these  studies. 

Two  genera  of  the  Scaphandridae,  Cylichnella 
Gabb,  1873  and  Utriculastra  Thiele,  1925,  have  dif- 
ferent shell  types.  Cylichnella  has  an  involuted 
spire  while  Utriculastra  possesses  a  projecting  apex 
of  varying  prominence  (Marcus,  1958;  Marcus, 
1977).  Marcus  (1977)  noted  that  the  gizzard  and 
radula  of  members  of  both  genera  are  virtually 
identical  but  differentiated  the  genera  on  the  basis 
of  several  other  criteria.  Marcus  (1977)  described 
two  subgenera,  U.  (Utriculastra)  and  U.  (Tor- 
mtstra).  My  preliminary  examinations  suggest  that 
a  more  detailed  analysis  of  the  status  of  Cylichnella 
and  Utriculastra  is  warranted.  The  work  of  Marcus 
(1977)  supplied  an  excellent  analysis  of 
Utriculastra  and  its  component  subgenera  and 
species  and  provides  the  basis  of  comparison  for  the 
work  presented  in  this  paper. 

I  would  like  to  thank  Dr.  Ruth  Turner  of  Har- 
vard University  for  her  encouragement  and  for  her 
critical  comments,  Dr.  Eveline  Marcus  of  the 
University  of  Sao  Paulo,  Brazil  for  her  suggestions 
and  enthusiasm,  Dr.  M.  Patricia  Morse  of  North- 
eastern University,  Mr.  Kee  Muschenheim  of  Yale 
University  and  Mr.  Gale  Sphon  of  the  Los  Angeles 

County  Museum  for  providing  specimens.  I  would 
particularly  like  to  thank  Dr.  Larry  Harris  of  the 
University  of  the  New  Hampshire  for  his  guidance 
and  friendship  and  for  his  help  in  collecting 
specimens  in  Nova  Scotia. 

Three  specimens  of  Cylichnella  cerealis  (Gould, 
1852)  were  collected  from  Bodega  Harbor,  Bodega 
Bay,  California  (lat.  38°18'N.;  long.  123°03'  W.)  on 
June  17,  1976.  Numerous  specimens  of  C.  inculta 
(Gould,  1856)  were  collected  from  Morro  Bay, 
California  (lat.  35°20'  N.;  long.  120°50'  W.)  on  July 
17,  1976.  C.  canaliculata  (Say,  1826)  was  collected 
on  August  17,  19,  26, 1977  from  several  localities  in 
Nova  Scotia  and  New  Brunswick,  and  on  Sep- 
tember 3,  1977  from  Pt.  Judith,  Rhode  Island  (lat. 
4r24'  N.;  long.  72°30'  W.)  Additional  specimens  of 
C.  canalicxdata  from  Long  Island  Sound  were 
provided  by  Mr.  Kee  Muschenheim.  Several 
specimens  of  C  culcitella  (Gould,  1852)  from  San 
Miguel  Island,  California,  (lat.  35°59'  N.;  120°25' 
W.)  were  loaned  by  the  Los  Angeles  County 
Museum.  Three  specimens  of  C.  bidentata  (Orbigny, 
1841)  from  the  Eveline  Marcus  collection  were 
made  available  by  the  Department  of  Mollusks, 
Museum  of  Comparative  Zoology,  Harvard  Univer- 
sity. Numerous  specimens  of  C.  oryza  (Totten, 
1835),  dredged  from  Long  Island  Sound,  were 
provided  by  Mr.  Kee  Muschenheim. 

Specimens  were  observed  alive  whenever 
possible  and  were  dissected  for  morphological  com- 
parison. Several  (circa  5-10)  individuals  of  each 

86      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

species  were  dissected  to  determine  intra  as  well  as 
interspecific  variation.  The  anatomy  of  the  shell, 
postero-lateral  e.xtension  of  the  mantle,  radula. 
jaw,  gizzard  plates,  nervous  system  and  reproduc- 
tive system  was  studied  for  each  species. 

Cylichnella  Gabb,  1873 

type  species:  Bulla  bidentata  Orbigny ,  1841 
1.  C.  ranaliculata  (Say.  1826) 

Specimens  collected  from  three  different 
localities  in  New  Brunswick  and  Nova  Scotia 
exhibited  different  shell  characteristics.  Specimens 
fi-om  Parlee  Beach.  Shediac,  N.  B.  (lat.  46°  12'  N.; 
long.  64°30'  W.)  an  open  sandy  beach  on  the  Nor- 
thumberland Strait,  have  a  spire  which  is  elongate 
and  clean;  those  from  Pictou  Harbor,  N.  S.,  (lat. 
45°40'  N.;  long.  62° 45'  W.)  a  quiet  area  of  mixed 
fine  sand  and  mud  have  an  elongate  spire  which  is 
covered  with  sand  and  mud;  and  the  spires  of  all 
specimens  (100)  from  Bras  d'Or  Lake,  N.  S.,  (lat. 
46°05'  N.;  long.  60° 48'  W.)  a  large  calm  estuary,  are 
almost  completely  eroded.  The  shell  ranges  from  3..5 
to  6.0  mm  in  length.  In  all  cases  the  periostracum  is 
thin  and  transparent.  The  postero-lateral  elabora- 
tion of  the  mantle  edge  is  .short. 

The  radular  formula  in  five  specimens  ranges 
from  12-1.")  X  1.  1.  1.  Tlie  jaws  are  cuticular  and 
possess  platelets  as  depicted  by  Marcus  (1977).  The 
gizzard  plates  of  C.  canaliculata  are  similar  to  that 
described  by  Marcus  (1977)  with  a  wide  heart 
shaped  dorsal  plate  and  two  narrow  sub-equal 
latero-ventral  plates.  In  six  specimens  observed  the 
large  gizzard  plates  ranged  in  length  from  .85  to  1.0 
mm  while  the  lateral  plates  ranged  from  .95  to  1.25 
mm  in  length. 

The  nervous  system  (Fig.  1)  consists  of  two  large 
cerebral  and  two  large  pedal  ganglia.  The  cerebral 
and  pedal  commissures  are  approximately  equal  in 
length.  The  left  and  right  pleural  ganglia  are  small 
and  connect  to  the  cerebal  and  pedal  ganglia.  Im- 
mediately posterior  to  the  right  pleural  ganglion 
lies  the  right  parietal  ganglion.  From  there  the 
right  visceral  nerve  runs  posteriorly  to  the  suprain- 
testinal  ganglion  which  is  situated  at  the  level  of 
the  mid-portion  of  the  gizzard.  At  the  dorsal  .sur- 
face of  the  ganglion  the  short  osphradial  nerve  con- 
nects with  the  vestigial  osphradium.  Near  its 
posterior  limit  the  right  visceral  nerve  crosses  the 

left  visceral  nerve  dorsally  and  loops  anteriorly  to 
the  small  genital  ganglion.  From  the  genital 
ganglion  emanates  the  genital  nerve  and  the  left 
visceral  nerve.  After  a  moderate  distance  the  left 
visceral  ner\'e  gives  rise  to  the  closely  as.sociated 
visceral  and  sub-intestinal  ganglia.  Midway  be- 
tween the  left  pleural  ganglion  and  the  sub-intes- 
tinal ganglion  the  left  visceral  nerve  gives  rise  to 
the  pallial  nerve.  At  this  juncture  the  visceral 
nerve  is  slightly  thickened  yet  does  not  form  a 
distinct  pallial  ganglion. 

The  reproductive  system  of  C.  canaliculata  (Fig. 
2)  consists  of  a  series  of  diffuse  lobes  of  the  ovotestis 
which  are  interdigitated  with  the  digestive  gland. 
The  narrow  pre-ampuUary  duct  is  short  and  widens 
intf)  an  ampulla  consisting  of  numerous  con- 
volutions. The  ampulla  narrows  into  an  elongate 
and  relatively  straight  post-ampullary  duct.  A 
semiserial  receptaculum  seminis  (terminology 
following  Edmunds.  1970)  enters  the  post- 
ampullary  duct  which  continues  distally  to  the 
common  genital  atrium.  Also  entering  the  com- 
mon atrium  are  the  large  female  accessory  organs, 
the  albumen  and  mucus  glands.  The  duct  of  the 
spherical  bursa  copulatrix  also  enters  the  common 
atrium  at  this  point.  From  the  gonopore  an  open 
seminal  groove  runs  anteriorly  to  the  protrusible 
cephalic  penis. 

2.  C.  inculta  (Gould,  1856) 

The  shell  of  C.  inculta  has  an  elevated  spire.  The 
protoconch  may  be  present  or  eroded.  The 
periostracum  is  transparent.  In  the  forty  specimens 
studied  the  shell  is  3.5  to  6.0  mm  long.  The  postero- 
lateral margin  of  the  mantle  is  produced  into  a 
short  extension.  The  radular  formula  in  four 
specimens  varies  from  18-20  X  1.1.1.  The  jaws  are 
thin  and  cuticular  and  possess  platelets  as  depicted 
by  Marcus  (1977).  The  gizzard  is  similar  to  that 
described  by  Marcus  (1977).  The  dorsal  plate  is 
broad  and  heart  shaped  and  ranges  from  .80-1.05 
mm  in  length.  The  narrow  paired  gizzard  plates  are 
.9.5 to  1.10mm  in  length. 

The  central  nervous  system  and  reproductive 
system  are  indistinguishable  from  those  of  C. 
canaliculata  with  the  exception  of  the  penis.  In  C. 
inculta  the  prostate  is  thick  and  elongate  while  in 
C.  canaliculata  it  is  much  thinner  and  shorter. 

Vol.  98  (2-3) 

April  23, 1979 

THE  NAUTILUS      87 

FIGS.  1-4.  Cylichnella  canaliculata  (Saij).  1,  central  nervous 
syxtem  (scale  1.0  mm).  2,  reproductive  system  (scale  0.5  mm). 
3,  Cylichnella  culcitella  fGoiiUI)  (xralr  1.0).  3a,  receptafuliim 

Legend  to  Lettering 

ag-albumen  gland 
bc-bursa  copulatrix 
c-eerebral  ganglia 
g-genital  ganglion 
ga-genital  aperture 
me-membrane  gland 
mg-mucus  gland 


pa-parietal  ganglion 
pl-pleural  ganglion 
pr- prostate 

rs-receptaeulum  seminis 
sb-subintestinal  ganglion 
sp-supraintestinal  ganglion 
v-visceral  ganglion 

seminis.  3b,  entire  reproductive  system.  4,  Cylichnella  biden- 
tata  (Orhigny)  (scale  0.2  mm),  reproductive  system. 

3.  C.  culcitella  (Gould,  1852) 

The  shell  is  9.5  to  15.0  mm  in  length  in  the  20 
specimens  observed.  The  spire  is  slightly  to 
moderately  elevated.  The  periostracum  is  trans- 
parent-browTi  with  numerous  spiral  striations. 
The  length  of  the  po.stero-lateral  mantle  e.xtension 
varies  from  moderate  to  extremely  long.  It  recurves 
to  the  right  side  of  the  animal  and  extends  ven- 
trally  to  the  ventral  surface  of  the  body  whorl. 

88      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

In  C.  culcitella  there  are  23,  24  and  28  pairs  of 
lateral  teeth  in  three  individuals  observed.  In  the 
specimen  with  24  pairs  of  lateral  teeth  there  is  a 
row  of  14  small,  rectangular  rachidian  teeth,  while 
rachidians  are  entirely  absent  in  the  other  two  in- 
dividuals from  the  same  collection.  There  are  55  to 
66  denticles  along  the  entire  margin  of  the  lateral 
teeth.  The  jaws  consist  of  a  thin  membranous 
cuticle  without  platelets.  In  four  specimens  ob- 
served the  small  unequal  gizzard  plate  is  laterally 
flattened  and  is  1.6  to  2.9  mm  long.  The  large  sub- 
equal  gizzard  plates  are  2.4  to  4.9  mm  long. 

The  reproductive  system  of  C.  culcitella  is 
similar  to  that  of  C.  canaliculata  except  that  the 
receptaculum  seminis  is  serial  in  one  specimen 
(Fig.  3b)  and  semi-serial  in  two  other  specimens 
(Fig.  'ia).  The  penis  and  prostate  in  three  specimens 
observed  is  similar  to  that  described  by  Marcus 
(1977)  and  ranges  from  7  to  13  mm  in  length. 

4.  C.  cerealis  (Gould,  1852) 

The  shell  is  6.5  to  11.0  mm  in  length  and  has  a 
moderately  elevated  spire.  The  periostracum  is 
transparent  with  brown  spiral  striations  of  varying 
prominence.  The  postero-lateral  extension  of  the 
mantle  is  elongate  and  recurves  to  the  left  along 
the  dorsal  surface  of  the  body  whorl. 

The  radula  in  the  three  specimens  observed  con- 
sists of  17,  19  and  21  pairs  of  lateral  teeth.  In  no 
case  is  there  any  trace  of  rachidian  teeth.  The  jaws 
are  thin  and  membranous  without  platelets.  In  the 
four  specimens  observed  the  small,  uneven  gizzard 
plate  is  dorso-ventrally  flattened  and  1.0  to  1.5  mm 
long.  The  large  subequal  plates  are  1.5  to  2.5  mm 

The  nervous  system  is  identical  to  that  described 
for  C.  canaliculata. 

The  reproductive  system  is  the  same  as  in  C. 
canaliculata  except  that  the  receptaculum  seminis 
in  one  specimen  is  serial  and  semi -serial  in 
another,  as  in  C.  culcitella.  In  the  three  specimens 
studied  the  penis  consists  of  an  elongate,  thickened 
prostate  and  a  conical  papilla  which  lacks 
papulations.  The  penis  ranges  from  8  to  12  mm  in 

5.  Cylichnella  bidentata  (Orbigny,  1841) 

The  shell  is  elongate  and  cylindrical  with  a 
bulloid  apex.  In  the  three  specimens  studied  the 
shell  is  2.8  to  3.1  mm  long  and  1.4  to  1.6  mm  wide. 
The  periostracum  is  thin  and  transparent  without 

striations.  The  postero-lateral  extension  of  the 
mantle  is  of  a  moderate  length. 

The  radular  formula  in  two  specimens  dissected 
consists  of  14  and  15  X  1.1.1.  The  jaws  are 
thickened  at  the  anterior  edge  but  lack  any 
platelets.  The  gizzard  consists  of  a  wide  heart 
shaped  dorsal  plate  which  in  two  individuals 
ranges  from  .55  to  1.0  mm  in  length.  The  narrow 
paired  plates  range  from  0.6  to  1.0  mm  in  length. 

The  nervous  system  and  the  reproductive  system 
(Fig.  4)  are  not  significantly  different  from  that  of 
Cylichnella  canaliculata.  The  penis  is  identical  to 
that  described  by  Marcus  (1958). 
6.  C:  oryza  (Totten,  1835) 

The  shell  (Fig.  5)  is  orbicular  with  a  depressed 
bulloid  apex.  The  preserved  animals  vary  in  length 
from  1.4  to  2.8  mm  and  0.7  to  2.0  mm  in  width.  The 
postero-lateral  extension  of  the  mantle  is  ex- 
tremely short. 

In  the  two  specimens  examined  the  radula  (Fig. 
6)  has  a  formula  of  16-17  X  1.1.1.  There  are  10  to  16 
denticles  on  the  inner  margin  of  the  laterals.  The 
jaws  consist  of  a  thin  chitinous  cuticle  which  lacks 
platelets.  The  gizzard  (Fig.  7)  consists  of  a  large 
heart  shaped  dorsal  plate  and  two  smaller, 
subequal  ventro-lateral  plates.  The  dorsal  plate  in 
the  one  specimen  examined  is  1.35  mm  long  and  .97 
mm  wide.  The  two  subequal  plates  are  1.25  mm  and 
1.22  mm  in  length  and  .51  mm  and  .50  mm  wide, 

The  central  nervous  system  (Fig.  8)  appears  to  be 
entirely  euthyneurous  as  the  right  visceral  nerve 
does  not  cross  the  left  visceral  nerve.  The  relation- 
ships of  the  ganglia  are  similar  to  those  of  C. 
canaliculata  except  that  the  visceral  nerves  are 

The  reproductive  system  of  C.  oryza  (Fig.  9,  10) 
closely  resembles  that  of  C.  canaliculata.  The  only 
difference  is  that  the  receptaculum  seminis  is 
spherical  with  an  elongate  duct  in  both  specimens 
dissected.  The  penis  consists  of  a  wide  prostate 
which  narrows  anteriorly  for  most  of  its  length. 
The  penial  papilla  is  broad  without  any  armature 
or  papillae. 


The  morphological  similarities  between  the 
species  described  is  striking.  Marcus  (1977,  p.  17) 
noted  that  the  radular  teeth  and  gizzard  plates  of 
Cylichnella    canaliculata    (as    Utriculastra)    and 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      89 

FIGS.  5-10,  Cylichnella  oryza  (Totten).  5,  shell  (scale  0.3  mm). 
6,  radular  teeth  (scale  10  mj/  /  7,  gizzard  plates  (scale  0.5 

mm).  8,  central  nervous  system  (scale  0.3).  9,  penis  and  pro- 
state (scale  0.1  mm).  10,  reproductive  system  (scale  0.25  mm). 

90      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

Cylichnella  hidentata  were  identical  yet  stated 
that  "the  depressed  apex  (of  the  shell),  the  shape  of 
the  head  shield,  posterior  adherence  and  the  male 
organ  are  different  in  both  forms  and  justify 
generic  separation."  A  detailed  examination  of 
these  differences  is  required. 

The  presence  of  a  bulloid  shell  in  Cylichnella  ver- 
sus an  elevated  spire  in  Utriculastra  appears  to  be 
a  useful  character  for  generic  separation.  However, 
if  one  examines  the  shells  of  species  which  Marcus 
considered  as  members  of  Utriculastra  one  en- 
counters a  wide  range  of  form.  C.  rolleri  (Marcus, 
1977)  generally  h;i.s  an  e.xtremely  elongate  spire 
(unpublished  data)  while  in  C.  eximia  the  spire  is 
scarcely  elevated  (Marcus,  1977).  Most  other  species 
are  somewhat  intermediate  between  these  two  in 
spire  elevation. 

The  shape  of  the  head  shield  in  C.  carmliculata, 
when  fully  extended,  is  rectangular  and  more 
elongate  than  shown  by  Marcus  (1977,  Fig.  23).  The 
posterior  lobes  of  the  head  shield  are  rounded  in  C. 
canaliculata  whereas  they  are  acutely  pointed  in  C. 
hidentata.  The  lobes  of  C.  rolleri.  however,  are 
elongate  and  acute  as  in  C.  hidentata.  I  am  unable 
to  discern  any  consistent  difference  in  the  shape  of 
the  head  shield  between  species  considered  as 
Cylichnella  and  Utrifulmtrn  by  Marcus  (1977). 

It  appears  to  me  that  the  "posterior  adherence" 
(Marcus,  1958)  of  Cylichnella  bidentatn  is 
homologous  with  the  "cloacal  tentacle"  (Marcus, 
1977)  found  in  C.  cerealis,  C.  culcitella  and  Tor- 
natina  conspicua.  I  prefer  the  term  posterior  ex- 
tension of  the  mantle.  Cylichnella  oryza  lacks  any 
noticeable  extension  of  the  mantle  while  in  C.  in- 
cut ta  and  C.  canaliculata  it  is  extremely  short.  In 
specimens  of  C.  cerealis  from  Bodega  Harbor  the 
extension  was  as  highly  elaborated  as  in  Tomatina 
conspicua.  The  length  of  the  extension  varies  in 
specimens  of  C  culcitella  from  San  Miguel  Island. 
There  seems  to  be  no  consistent  difference  between 
Cylichnella  and  Utriculastra  with  respect  to  this 

The  final  character  on  which  Marcus  (1977) 
based  her  separation  of  Cylichnella  and 
Utriculastra  was  the  structure  of  the  penis.  The 
papilla  of  C.  hidentata  bears  a  row  of  papillae  along 
its  margin  (Marcus,  1958,  present  study).  In  C. 
culcitella  the  penis  contains  similar  papulations 
(Marcus,    1977).    The    penis    of    C.    inculta,    C. 

rnnnlinilntn  and  C  aryza  lacks  any  papulations. 
Marcus  (1974)  has  shown  that  some  species  of 
Scaphander  posses  papulations  on  the  penial 
papilla  while  others  lack  them  entirely.  Simi- 
larly, Rudman  (1974)  has  shown  that  Aglnja 
ocelligera  has  a  penial  papilla  with  numerous 
papulations  while  other  members  of  the  genus 
have  a  naked  penis.  There  seems  to  be  little  basis 
for  separation  of  Cylichnella  and  Utriculastra 
with  regard  to  the  penis. 

The  nervous  systems  of  all  species  of  Cylich- 
nella in  this  study  were  virtually  identical  with 
the  exception  of  C.  oryza  which  is  completely 
euthyneurous  yet  has  the  same  configuration  of 
ganglia.  Though  all  other  species  observed  in  this 
study,  including  C  hidentata  differ  slightly  from 
C  (rryza  their  differences  are  not  regarded  as 
having  taxonomic  importance. 

In  the  examination  of  the  reproductive  systems 
of  the  six  species  observed  in  this  study  the  most 
substantial  difference  occurred  within  the  species, 
C  culcitella  and  C  cerealis.  In  both  species  the 
receptaculum  seminis  may  be  either  serial  or  semi- 
serial.  Since  the  greatest  difference  observed  is  of 
an  intraspecific  nature  there  is  no  basis  for 
separating  genera. 

When  the  observed  species  of  Cylichnella  are 
compared  there  is  no  characteristic  which  clearly 
differentiates  them  at  the  supraspecific  level.  The 
differences  in  the  radula  and  gizzard  of  Marcus' 
two  subgenera  Utriculastra.  U  (Utriculastra)  and 
['.  (Tonuistra).  are  more  substantial  than  those 
between  U.  (Utriculastra)  and  Cylichnella.  I 
feel  that  the  taxa  Cylichnella  and  Utricula.'^tm 
form  a  natural,  monophyletic  genus  and  should 
be  regarded  as  Cylinchnella  Gabb.  1873,  on  the 
basis  of  priority.  Utriculastra  is  regarded  as  the 
junior  synonym. 

Marcus  (1977)  described  two  subgenera  of 
Utriculastra,  U.  (Utriculastra)  and  U.  (Tomastra). 
U  (Utriculastra)  is  characterized  by  having  a 
deltoid  unpaired  gizzard  plate  while  ['.  (Tor- 
nastra)  has  a  round  unpaired  plate.  However,  the 
vast  majority  of  morphological  characteristics  (e.g. 
shell,  radula,  nervous  and  reproductive  systems) 
are  virtually  identical  between  species  placed  in 
both  subgenera.  In  Philine,  the  monotypic  genus  of 
the  closely  allied  Philinidae,  the  shape  of  the  giz- 
zard plates  varies  considerably  or  may  be  absent 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      91 

but  no  subgeneric  separation  is  made.  I  feel  that 
the  separation  of  Cylichnella  is  not  useful  as  it  ap- 
pears to  form  a  natural  generic  taxon.  I  therefore 
also  supress  Tomastra  as  a  junior  synon>Tn  of 
Ci//(W;«e//aGabb,  1872. 

The  large  number  of  synonyms  of  Cylichnella 
canaiieulata  attests  to  the  taxonomic  confusion 
regarding  this  species.  Wells  and  Wells  (1962) 
examined  numerous  specimens  of  Cylichnella  from 
North  Carolina.  They  maintained  that  two  species 
were  present,  Retttsa  canaiieulata  and  Acteocina 
candei.  Although  closely  allied,  the  species  were 
placed  in  separate  genera,  as  the  absence  of  a 
radula  in  Retusa  ohtusa.  the  type  species  oi Rctusa. 
had  not  been  verified.  Subsequent  study  has  con- 
firmed that  a  radula  is  wanting  in  Retusa  ohtusa 
(personal  observation)  and  that  it  is  inappro- 
priate to  place  C.  canaiieulata  in  Retusa.  Wells  and 
Wells  regarded  the  two  species  as  being  distinct  on 
the  following  bases:  slight  conchological  dif- 
ferences, the  presence  of  more  numerous  denticles 
on  the  rachidian  and  lateral  teeth  of  the  radula  in 
C  candei  and  an  offehore  distribution  of  C.  candei 
vidth  an  estuarine,  inshore  distribution  in  C. 
canaiieulata.  Wells  and  Wells  described  an  entirely 
contained  developmental  pattern  for  C. 
canaiieulata.  Franz  (1971)  examined  the  develop- 
mental biologv'  of  C.  canaiieulata  from  Connecticut 
and  determined  that  the  species  e.xhibits  a 
plankotrophic  pattern.  He  offered  several  possible 
explanations  for  this  discrepancy.  My  observations 
of  an  estuarine  population  in  Pictou  Harbor,  Nova 
Scotia,  confirm  that  the  species  has  planktotrophic 
development.  Marcus  (1977)  discussed  the  criteria 
used  to  separate  the  two  species  and  suggested  that 
intermediates  in  conchological  and  radular  mor- 
phology are  common.  She  also  noted  that  these 
characteristics  cannot  be  correlated  with  estuarine 
or  offshore  distribution  and  that  C.  candei  should 
be  regarded  as  a  junior  synonym  of  C.  canaiieulata. 
My  observations  of  C.  canaiieulata  are  entirely  sup- 
portive of  Marcus'  findings. 

Cylichnella  canaiieulata  is  morphologically  very 
similar  to  C.  inculta.  C.  canaiieulata  has  12  to  15 
rows  of  radular  teeth  while  C.  inculta  has  17  to  20 
rows.  The  large  dorsal  gizzard  plate  of  C.  incidta  is 
broader  than  in  C.  canaiieulata  and  also  contains  a 
proportionately  larger  thickened  central  portion. 
The  penis  of  C.  iiiculta  contains  a  thicker  and 

longer  prostate  than  that  of  C.  canaiieulata.  While 
these  differences  are  minor  they  do  appear  to  be 
consistent  and  warrant  specific  separation. 

Marcus  (1977)  stated  that  C.  cereali's  was  distinct 
from  C.  eximia  and  C.  culcitella.  The  material  from 
Bodega  Harbor  supports  this  contention.  The  un- 
paired gizzard  plate  is  dorso-ventrally  flattened 
rather  than  laterally  compressed.  The  lateral  teeth 
in  C.  cerealis  possess  20  to  37  denticles  compared  to 
40  reported  for  C.  eximia  and  55  to  66  for  C. 
culcitella.  Ball's  (1922)  contention  that  C.  cerealis 
are  young  C.  culcitella  is  refuted  since  all 
specimens  collected  at  Bodega  Harbor  were 
sexually  mature  and  were  collected  with  egg 

The  separation  of  C.  eximia  and  C.  culcitella 
seems  more  difficult.  Marcus  (1977)  stated  that 
they  were  distinguished  by  their  radular  teeth, 
penis  and  gizzard,  yet  described  the  radula  of  C. 
culcitella  as  corresponding  "to  that  of  eximia".  The 
gizzard  plates  depicted  for  C.  culcitella  are  slightly 
more  oval  than  those  of  C.  eximia  (Marcus,  1977, 
figs.  57,  68,  69,  70,  74)  yet  specimens  from  San 
Miguel  Island  showed  similar  variation.  The  penis 
and  prostate  was  20  mm  long  in  C.  eximia  and  3 
mm  long  in  C.  culcitella  in  specimens  of  approx- 
imately equal  length.  Specimens  studied  in  this 
paper  had  penis  and  prostate  lengths  of  7.  9  and  13 
mm.  Due  to  the  intermediate  length  of  the  penis 
along  with  similar  morphology  of  the  other  systems 
the  two  species  are  here  considered  as  s>Tion>TTious 
with  C.  culcitella  (Gould,  1852)  having  priority. 

Based  on  the  anatomical  work  I  have  undertaken 
I  propose  the  following  taxonomic  arrangement: 

Genus  Cylichnella  Gabb,  1873 

Cylichtiella  Gabb.  187:3:  273.  {i\-pe  siiecies:  Biilln  hidoitnta  Or- 

bigny,  18-11) 
Utriailastra    Thiele,     1925:     235.    (type    species;     Volnaria 

canaiieulata  Say,  1826) 
Tamastra  Marcus,  1977:  5.  (tjTJe  species:  Bulla  eximia  Baird. 


Cylichnella  biden lata  (Orbigny,  1841) 

Bulla  bidentata  Orbigny,  1841. 

Cylichnella  bidentata  (Orbigny,  1841)  Gabb,  1873. 

Cylichnella  canaiieulata  (Say,  1826) 

Viiharia  canaiieulata  Say,  1826. 
Bulla  candei  Orbigny,  1841. 

92      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

Utriatlus  cavdiculatus  (Say.  1826)  Watson.  1886. 
Tormtina  cmdiculata  (Say.  1826)  Pilsbry.  1895. 
Tormtim  candei  (Orbigny.  1841)  Pilsbry.  189,5. 
Retusa  (i'triadastmjcanalicutata  (Say.  1826)Thiele.  1925. 
Artaeociyia  candei  (Orbigny.  1841)  Carcelles.  1944. 
Acteodna  canaliculata  (Say,  1826)  Perrv'  and  Schwengel.  19.55. 
Retusa  candei  (Orbigny,  1841)  Abbott,  19,58. 
Acteodna  candei  (Orbigny,  1841)  Wells  and  Wells.  1962. 
Utriailoftra  (i'triculastm)  canalicidata  (Say,  1826)  Marcus, 

Cylichnella  inculta  (Gould,  18.56) 

Tomatina  inculta  Gould,  18.56. 

Utricidaatra  H'trindastm) inculta  (Gould.  18.56)  Marcus.  1977. 

Cylichnella  cerealis  (Gould,  1852) 

Bulla  cerealis  Gould,  18.52 

Utriadastm  (Tornastral  cerealis  (Gould.  18.52)  Marcus.  1977. 

Cylichnella  culcitella  (Gould,  1852) 

Bulla ndcitetta  Gould.  ia52 

Btdlina eximia  Baird,  186.3. 

Utricidaatra  (Tomastra) culcitella  (Gould,  1&52)  Marcus,  1977. 

Utricidaatra  (Ti'mastra) erimia  (Baird.  18S3)  Marcus.  1977. 

Cylichnella  oryza  (Totten,  1835) 

Bulla  (rryzaTottenASS^. 

Cylichnella  oryza  (Totten,  1835)  Marcus,  1958. 

Cylichnella  knockeri  (E.  A.  Smith,  1872) 

Tomatina  knockeri  Smith,  1872 

Utriculastra  (Tormstra)  knockeri  (E.  A.  Smith.  1872)  Marcus, 

Cylichnella  roUeri  (Marcus,  1977) 

Utrindastra  (Tornastral  rolleri  Marcus,  1977. 

Other  species  possibly  belong  in  the  genus 
Cylichnella  (Marcus,  19.58:  8:  Marcus.  1977:(i)  but 
cannot  be  assigned  with  certainty  until  they  have 
been  studied  morphologically. 


Bouchet,  Philippe.  1975.  Opisthobranches  de  profondeur  de  I'o- 

cean    Atlantique.    I.    Cephalaspidea.    Cahiers   de    Biologie 

Marine  16:  m-'i^o. 
Dall.  William  H.  1922  A  note  on  Arteocina.  The  Nautilus  35:  96. 
Edmunds.  Malcolm.   1970.   Opisthobranchiate   Mollusca  from 

Tanzania.    II.    Ek)lidacea   (Cuthonidae.    Piseinotecidae   and 

Facelinidae).  I'nic.  Malac.  Sac.  Limdim  39:  15-.57. 
Franz.  David.  1971.  Development  and  metamorphosis  of  the 

gastropod  Acteocinn  canalicidata  (Say).  Trans.  Amer.  Micros. 

Soc.  90(2):  174-182 
Gabb,  William  M.  1873.  Description  of  some  new  genera  of 

Mollusca.  Proc.  Acad.  Nat  Sci.  Philadelphia  1872:  270-274. 
Marcus,  Ernst.   1956.   Notes  on  Opisthobranchia.  Bol.  Inst. 

Oceana.  S.  Pauh,  7(1958):  31-79. 
19.58.   On   western   Atlantic  opisthobranch 

gastropods.  Amer.  Mus.  Novitates,  no.  1906:  1-82. 
Marcus,  Eveline  duIBois-Reymond.  1974.  On  some  Cephalaspidea 

(Gastropoda:  Opisthobranchia)  from  the  western  and  middle 

Atlantic.  Bh//.  Mar.  Sci  14(2):  3(K)-371. 
1977.  On  the  genus  Tomatina  and  related  forms. 

Jofurn.  Moll  Stiidicx  (suppl.2):  1-.3.5. 
Rudman,  W.  B.  1971.  On  the  opisthobranch  genus  Haminoea 

Turton  and  Kingston.  Pacific  Sci.  25:  549-.S59. 
1973.    The    genus    Philine    (Opisthobranchia, 

Gastropoda).  Pnic.  Malac.  Snc.  London  40(3):  171-187. 
.  1974.  A  comparison  of  Chflidoiiura.  Navanax  and 

Aylaja  with  other  genera  of  the  .^gtajidae  (Opisthobranchia: 
Ga.stropoda).  Ziiol.  J.  IJniiean  Soc.  London  54:  178-212. 

Thiele.  .Johannes.  1925.  Gastropoda  der  Deutschen  Tiefsse- 
Expedition  Pt.  2.  Eiyebnisse  dcr  Deutschen  Tiefsee- 
Krpedition  17:  .37-382. 

Wells,  Harry  and  Mary  .lane  Wells.  1962.  The  distinction  be- 
tween Acteodna  candei  and  Retusa  canaliculata.  The 
Nautibis  75(3):  87-93. 


The  main  archives  for  the  American  Mala- 
cological Union  have  now  been  removed  from  the 
Delaware  Museum  of  Natural  History  and  placed 
in  more  convenient  and  accessible  quarters  in  the 
Department  of  Malacology,  Academy  of  Natural 
Sciences  of  Philadelphia,  19th  and  The  Parkway, 
Philadelphia,  PA  19103  (stewardship  is  in  the 
hands  of  Dr.  George  M.  Davis;  phone  1-21,5- 

Archives  Moved 

The  archives  contain  documents,  correspond- 
ence, photographs  and  information  on  about  1.50() 
professional  and  amateur  American  malacolo- 
gists,  and  are  available  for  e.xamination  by 
serious  students  of  historical  malacology.  New 
material,  e.specially  of  historical  value,  is  most 
welwme  at  the  new  center,  and  will  be  properly 
curated  and  preserved. 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      93 


Robert  S.  Prezant 

College  of  Marine  Studies 
University  of  Delaware 
Lewes,  Delaware  19958 


Sihall.  Clinical  pnijcctiims  of  the  periostmmm  cover  the  outer  shell  surfaces  (f 
the  hirnlve  Lyonsia  hyalina  Conrad.  These  radially  arranged  npimden  help  en- 
tangle a  mucoid  secretion  produced  hy  niaidle  glands  and  aid  in  the  retention  of 
sand  grains  u-hich  adhere  to  the  shell.  Vie  sand-corer  helps  stabilize  the  bivalve  in 
the  s^ibstriifuui  and  may  lend  some  protection  to  ds  thni  shell. 

Many  members  of  the  bivalve  family  Lyonsi- 
idae  have  the  curious  habit  of  attaching  sand 
grains  to  the  outside  of  their  shells.  Of  the  three 
genera  of  this  family,  Lyonsia  is  typically  found 
partially  buried  with  at  least  some  portion  of  its 
shell  covered  with  adhering  sediment.  Entodesma. 
a  rock-crevice  nestler,  and  Mytilimeria,  found 
embedded  within  compound  tunicates,  will  attach 
some  sediment  to  their  shells  if  grown  within  a 
sand  substratum  (Yonge,  1952).  The  ability  of 
Lyonsia  to  glue  sand  to  its  valves  was  previously 
attributed  to  a  minutely  fringed  (Morris,  1973; 
Emerson  and  Jacobson,  1976)  or  sticky  (Yonge, 
1952)  periostracum.  Prezant  (1979)  showed  that 
small,  multicellular  glands  which  line  the  mantle 
edge  of  L.  hyalina  secrete  a  mucoid  product  over 
the  periostracum,  and  it  is  this  which  is  responsi- 
ble for  adhesion  of  sand. 

The  superfamily  Pandoracea  has  many  in- 
faunal  genera,  including  Lyonsia,  which  are 
described  as  having  "granular"  shell  surfaces.  The 
granulations  or  spinulations  increase  shell  sur- 
face area  and  help  stabilize  the  bivalve  within 
the  substratum  (Aller,  1974).  The  small  spines  of 
Lyonsia  are  often  obscured  by  adhering  sand,  and 
are  thus  not  exposed  to  the  substratum  to  aid  in 
stabilization.  This  investigation  was  thus  de- 
signed to  examine  the  role  of  these  minute  pro- 
jections relative  to  the  attachment  of  sediment  to 
the  shell  of  L.  hyalina. 

'University  of  Delaware,  College  of  Marine  Studies  Contribu- 
tion No.  131. 


Lyonsia  hyalina  were  collected  from  Delaware 
Bay  from  a  muddy-sand  substratum  at  a  depth  of 
about  15  meters.  Shells  were  gently  cleared  of 
most  adhering  sand  grains  with  a  fine  camel's 
hair  brush.  Valves  were  carefully  opened  and  the 
animal  removed.  Shells  were  then  rinsed  in 
distilled  water,  and  some  were  dipped  in  0.53% 
sodium  hypochlorite  (10%  commercial  Clorox) 
and  some  in  20%  1  N  hydrochloric  acid  for  30 
seconds,  and  again  rinsed  in  distilled  water. 
Valves  were  then  dried  for  48  hours  in  a  60°C 
oven.  Dry  shells  were  fractured,  and  fragments 
were  mounted  on  scanning  electron  microscope 
stubs  with  silver  paint,  coated  with  gold,  and  ex- 
amined on  a  Cambridge  scanning  electron 


The  nacreous  shell  of  Lyonsia  hyalina  is  thin 
and  fragile  but  has  a  well  developed  periostracum 
with  numerous  periostracal  striations  which 
radiate  from  the  umbones.  A  surface  view  at  low- 
magnification  of  a  partially  cleaned  shell  (Fig.  1) 
reveals  the  prominent  striations  and  minute 
spines  which  run  parallel  to  the  radial  sculptur- 
ing. There  are  7  to  8  columns  of  these  spinules 
between  each  pair  of  periostracal  striations. 
Mucus,  secreted  by  mantle  glands  (Prezant,  1979), 
forms  a  tight  web  along  the  radial  striations  (Fig. 
2)  and  is  further  entangled  by  the  small  spines. 

The  exceedingly  small  spinules  are  truncated  at 
their  tips  (Figs.  3  and  4),  and  average  5.5  ycm  in 
height  and  7.5  \xm  in  width  at  their  base  in  a 

94      THE  NAUTILUS 

April  23. 1979 

Vol.  93  (2-3) 

bivalve  14  mm  limK.  The  base  of  each  spinule  is 
sunken  into  a  slight  depression  of  the  underlying 
supporting  shell  (Fig.  3).  The  spinules,  which  are 
highly  regimented  in  distribution  (Fig.  5),  aver- 
age a  distance  of  15  i/m  from  one  to  another  in 
either  direction.  In  the  Cloroxed  specimen  (Fig. 
6),  the  spinules  have  been  partially  dissolved, 
especially  peripherally  suggesting  an  organic 
component.  The  surface  of  the  periostracum  in 
the  treated  specimen  appears  pitted  (Fig.  6). 
Treatment  in  dilute  hydrochloric  acid  further 
reduces  the  spinules,  suggesting  a  calcareous  por- 
tion. The  latter  occurs  primarily  in  the  central 
region  of  the  spinule.  This  may  indicate  that  the 
spinule  is  composed  principally  of  an  aragonitic 
core  surrounded  by  periostracum. 

Adhesion  of  foreign  particles  to  the  shell  is 
aided  by  the  large  number  of  truncated  spinules 
which  help  entangle  the  mucoid  secretion 
generated  by  the  mantle  glands.  The  viscous 
mucus  is  laid  down  above,  but  in  conjunction 
with,  the  periostracum. 


Unlike  the  spinules  of  Laternula  flexuosa, 
another  member  of  the  Pandoracea,  those  of  Li/on- 
siu  are  not  "prefabricated"  in  the  mantle  (Aller, 
1974),  but  are  laid  down  along  with  the  rather 
thin  periostracum.  This  being  the  case,  the  spi- 
nules are  calcified  periostracal  components  as 
defined  recently  by  Carter  (1978).  Allen  and 
Turner  (1974)  discussed  several  Verticordiids 
possessing  mantle  glands,  which  attach  sediment 
to  their  shells,  and  have  calcareous  spinules 
which  may  be  preformed.  Aller  (1974)  considered 
attachment  of  external  particles  to  the  shell  a 
supplementation,  using  "prefabricated"  ex- 
traneous components  in  place  of  naturally 
"prefabricated"  spines.  The  latter  author  viewed 
such    supplementation,    whether    foreign    or 

natural,  as  a  consistent  theme  within  the  Pan- 

The  external  adhesive  properties  of  valves  of 
most  Lyonsiids  produces  greater  surface  re- 
sistance through  attachment  of  sand  grains,  and 
thereby  greater  stability  within  the  substratum. 
TTie  sand  cover  of  Lyomna  hyalinn.  and  most  like- 
ly all  other  species  of  Lyonsia,  may  act  secondari- 
ly as  an  armor  protecting  the  thin  shell,  and  sedi- 
ment adhering  around  the  otherwise  exposed  si- 
phonal  region  may  act  as  a  defensive  barrier  or 


I  wish  to  thank  Dr.  M.  R.  Carriker  for  reading 
the  manuscript,  G.  T.  Entrot  for  help  with  the 
scanning  electron  microscope  and  P.  Savage  for 
tj-ping  the  manuscript. 


Allen,  J.  A.  and  J.  F.  Turner.  1974.  On  the  functional  mor- 
phology of  the  family  Verticordiidae  (Bivalvia)  with 
descriptions  of  new  species  from  the  abyssal  Atlantic.  Phil. 
Trans.  R,ni.  Sm::  London  R  268:  401-.5.%. 

Aller,  R.  C.  1974.  Prefabrication  of  shell  ornamentation  in  the 
bivalve  Laternula.  Lethaia  7:  43-56. 

Carter,  J.  G.  1978.  Ecology  and  Evolution  of  the 
Gastrochaenacea  (Mollusca;  BivalVia)  with  Notes  of  the 
Evolution  of  the  Endolithic  Habitat.  B>dl.  Peabody  Mux.  1-92. 67  figs. 

Emerson.  B.  and  M.  K.  Jacobson.  1976.  American  Museum  of 
Natural  History  Guide  to  Shells.  A.  A.  Knopf  Inc.,  N.Y.,  482 

Morris.  P.  A.  1973.  A  Field  Guide  to  Sheik  of  the  Atlantic 
and  Chdf  Coasts  and  the  West  Indies.  H.  Mifflin  Co.,  Boston, 
330  pp. 

Prezant,  R.  S.  1979.  The  structure  and  function  of  the  radial 
mantle  glands  of  Lyonsia  hyalina  (Bivalia:  Anomal- 
odesmata).  ./m/r  Zool.  London  187:  In  Press, 

Yonge,  C.  M.  1952.  Structure  and  adaptation  in  Lntodeitma 
sarifola  (Baird)  and  Mytilimpria  nuttatlii  Conrad  -  with  a 
discussion  on  evolution  within  the  family  Lyonsiidae 
(P^ulamellibranchia).  Univ.  Cal.  Pub.  Zool.  55:  439-450. 

FIGS.  1-6.  1,  Surface  vieiv  of  a  partially  cleaned  shell  o/ Lyonsia  hyalina.  Several  sand  grains  remain  adhered  to  the  mucoid 
coat  which  covers  much  of  the  periostracum.  The  prominent  radial  striations  of  the  periostracum  and  the  xmall  spinules  which 
run  parallel  to  them  are  evident.  75X.  2,  Magnified  view  of  the  strand4ike  mucoid  secretion  which  ftmns  a  webbed  pattern 
along  the  radial  striations  of  the  periostracum.  6iOX.  3,  A  fi-actured  section  through  the  shell  ofh.  hyalina  revealing  the  trun- 
cated nature  of  the  /leriostmcal  spinules.  The  underlying  nacre  and  tnyostracum  are  also  ei-ident.  760X.  4,  Magnified  view  of  a 
fractured  spinule  showing  its  confluence  with  the  periosttrwum.  .VCK)X.  5,  An  oblique  surface  view  of  the  periostracum  showing 
alignment  of  the  spinules.  KXlflX.  6,  FolUnring  treatment  in  sodium  hypochlorite  the  xpinules  were  dissolved  revealing  their 
organic  nature.  This  micrograph  also  shows  the  pitted  outer  surface  of  the  shell  after  removal  of  the  m  ucoid  coat.  1200X. 

Vol.  93  (2-3) 

April  23, 1979 

THE  NAUTILUS      95 


Sb^  |m^  :V  i 

Explanation  ov  (iippimtr  page  (Shell  Spinules  of  the  Bivalve.  Lyonsia  hyalina) 

96      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 


William  J.  Clench 

Honorary  Curator  of  Malacology 
Museum  of  Comparative  Zoology 
Cambridge,  Massachusetts  02138 

The  Andrew  Garrett  Shell  Collection 

The  Garrett  collection  of  land  and  marine  shells, 
together  with  Garrett's  conchological  library  and  a 
few  manuscripts,  but  not  his  journal,  were  pur- 
chased by  the  Bishop  Museum  in  Honolulu,  Hawaii, 
some  time  prior  to  1899.  Exact  data  concerning  this 
purchase  are  lacking.  Apparently,  the  items  were 
not  in  the  museum  in  1893,  when  the  natural  his- 
tory portion  of  the  "Preliminary  catalogue"  was 
printed,  for  under  marine  shells  only  the  Baldwin 
collection  and  some  specimens  from  the  Govern- 
ment Collection  were  mentioned,  but  they  may 
have  arrived  a  year  or  more  before  1899,  when  the 
first  mention  of  the  collection  is  made  in  printed 
records  of  the  museum.  Dr.  Wm.  T.  Brigham  had 
had  time  to  have  the  specimens  mounted  on  paste- 
board blocks  and  labels  printed  before  then. 

In  the  Spring  of  1899,  Dr.  Wm.  H.  Dall,  of  the  U. 
S.  National  Museum,  was  employed  by  the  Museum 
Trustees,  upon  recommendation  of  the  Director 
(Dr.  Brigham)  to  come  to  the  Bishop  Museum  and 
examine  the  collection.  He  arrived  August  16,  and 
spent  two  months  making  his  study  and  correcting 
the  nomenclature.  His  report  is  published  in  the 
Report  of  the  Director  for  1899  (Occasional  Papers, 
1(2):  10-13).  Dall  estimated  that  the  collection  con- 
tained about  25,000  specimens,  representing  be- 
tween 8,000  and  9,000  species,  about  one-fourth  of 
them  land  shells,  all  neatly  mounted  and  with 
printed  labels,  and  largely  with  localities,  at  least 
to  island  groups. 

Andrew  Garrett's  shell  collection  was  one  of  the 
most  romplete  for  Pacific  areas  of  that  period.  It 
formed  the  basis  for  many  early  descriptions  of 
species,  and  contains  a  number  of  type  specimens 
or  at  least  cotype  or  paratype  specimens  of  species 
described  by  W.  Harper  Pease  and  other  con- 
chologists  of  the  period.  Dr.  Dall  states  that  he 
simply  "corrected"  the  names  of  the  specimens. 

It  is  unfortunate  that  we  do  not  have  more  exact 
information  concerning  the  acquisition  of  these 

'Part  1  on  the  life  of  (larrett.  by  W.  Stephen  Thomas,  appeared 
in  the  previous  number  of  The  Nnntilnx.  vol.  93.  no.  1.  pp.  1.5-28. 

early  collections.  For  reasons  best  knovra  to 
himself.  Dr.  Brigham  made  only  meager  record  of 
early  accessions.  A  search  of  Trustees  records  was 
made  by  Dr.  Yoshio  Kondo  at  the  time  he  wrote  a 
memorial  to  Dr.  C.  Montague  Cooke,  Jr.,  and  he 
states  that  he  found  no  information  concerning  the 
purchase  of  the  Garrett  (Ibllection. 

Prepared  by  E.  H.  Bryan,  Jr. 

History  of  the  Andrew  Garrett  Collection 


Andrew  Garrett  died  in  Huahine,  Society  Islands, 
Nov.  1, 1887.  His  private  collection  of  shells  went 
on  sale. 

February  18,  1893:  Charles  R.  Bishop,  in  Wash- 
ington, D.C.,  wrote  to  Trustee  Hyde  [Bishop 
Estate  Letters  in.  Book  4,  pp.  56-58],  notifying 
him  that  he  had  "authorized  Mr.  Dorence  At- 
water  to  buy  the  Garrat  [sic]  collection  of  shells 
etc.  at  $5,000  if  found  to  be  in  good  order  and 
complete . . ." 

May-October,  1893:  Andrew  Garrett  collection 
received  by  the  Bishop  Museum.  This  date  is 
deduced  from  Brigham 's  correspondence  between 
March  and  December,  1893,  listing  the  Museum's 
needs  to  the  Trustees. 

1894-1899:  Collection  was  catalogued  by  Brigham 
(1894)  and  specimens  were  mounted,  vnth 
printed  labels,  on  cardboard. 

August,  1899:  Wm  H.  Dall  studied  A.  Garrett  col- 
lection. See  BPBM  Director's  Annual  Report  for 
1899  (Occas.  Papers  1(2):  10-13). 

1900  ff.:  Garrett  collection  was  in  the  [exhibit] 
cases  of  BPBM  (Director's  Annual  Report  for 
1900,  p.  8;  "A  Handbook  for  Visitors  .  .  ."  by 
Brigham,  1903). 

1905:  Garrett  Collection  was  partly  relabelled  in 
accordance  with  Dr.  Dall's  identification,  and 
was  rearranged  to  accord  with  the  new  system  of 
taxonomic  arrangement.  (Director's  Report  for 
1905,  p.  260). 

Vol.  93  (2-3) 

April  23. 1979 

THE  NAUTILUS      97 

1927:  Garrett's  land  Shells  were  removed  from  the 
showcases  in  Pobnesian  Hall  to  the  [Malacologj] 
laboraton,'.  (C.  M.  Cooke,  Jr.,  annual  report  to 
Director  for  1927). 

1930:  Mrs.  J.  G.  McAllister  copied  "Garrett's 
original  catalog  into  the  Museum  catalog  . . ."  (C. 
M.  Cooke,  Jr.,  Annual  Report  for  1930).  [Mrs. 
McAllister  did  not,  however,  number  the 
specimens  with  the  corresponding  catalog 
numbers;  catalog  numbers  are  01-8694.] 

1930-1970:  Garrett's  specimens  were  rearranged, 
re-identified,  re-surveyed,  re-exhibited,  etc.,  by 
various  workers  in  malacology. 

1972  onward:  Attempts  are  being  made  to  locate 
possible  types  and  to  designate  them  as  lec- 
tot\-pes  by  A.  Kay  and  D.  Fellows.  We  also  hope 
to  completely  determine  the  circumstances  by 
which  the  Museum  acquired  the  collection. 

Prepared  by:  Danielle  B.  Fellows 
11  December  1972 

Geographic  Names 

All  of  the  type  localities  of  Andrew  Garrett 
were  given  along  with  the  original  descriptions. 
Certain  of  these  names  have  changed  with  the 
passage  of  time  and  are  listed  below: 

Austral  Islands  are  now  Tubuai  Islands. 

Cook's  Islands  are  now  Cook  Islands. 

Kiva  —  This  locality  in  the  Fiji  Islands  has  not 
been  located.  It  has  been  suggested  that  this 
name  may  have  been  an  error  for  "Kioa",  a 
small  island  at  the  eastern  end  of  Vanua 
Le\ai  and  northwest  of  Taviuni  but  Garrett 
had  mentioned  this  locality  several  times  as 
"Kioa  shore  reefe".  It  is  possible  that  the 
name  Kiva  has  since  disappeared.  The  name 
Kiuva  or  Kiura  has  been  suggested  as  well 
(about  central  on  the  coast  at  the  eastern  end 
of  Viti  Levu). 

Paumotu,  Panmotu  and  Paumotus  Seas  or  Is- 
lands are  now  Tuamotu  Islands. 

Tivinni  —  is  Taviuni  or  Taveuni  Island. 

Viti  Islands  are  Fiji  Islands. 


AJC  —  American  Journal  of  Conchology 
ANSP  —  Academy  of  Natural  Sciences  of  Phil- 

BPBM  —  Bernice  P.  Bishop  Museum 

BSMF  —  Bulletin  Society  Malac.  France 

JANSP  —  Journal  Academy  Natural  Sciences 

JC  —  Journal  of  Conchology 

PANSP  —  Proceedings  Academy  Natural  Sci- 
ences Philadelphia 

PCANS  —  Proceedings  California  Academy  Nat- 
ural Sciences 

PCAS  —  Proceedings  California  Academy  Sci- 

PZS  —  Proceedings  Zoological  Society  London 

Garrett  included  several  manuscript  names  of 
W.  H.  Pease  in  the  synonymy  of  other  species  by 
Pease.  In  a  few  cases,  Garrett  described  the 
species  with  the  original  names.  The  credit  for 
these  species  go  to  Garrett  as  he  described  them 
as  well  as  added  the  figures. 

Pease,  like  many  others  during  these  early 
years  of  descriptive  zoology,  sent  as  gifts  or  ex- 
change a  great  deal  of  material  with  manuscript 
names,  much  of  which  was  never  described.  Spec- 
imens under  these  names  are  in  many  institu- 
tions, both  here  and  abroad,  and  Garrett's  work 
will  have  solved  many  of  these  nomenclature 
problems  for  future  workers. 

abbreriata.    Cithara.    1873,    PANSP.    p.    223.   pi.   3,    fig.   41 

(Paumotus  Isles). 
acuticostata,  "Mousson"  Garrett,  Partula,   1884.  JANSP,  (2) 

9:30,  pi.  2,  fig.  13  a-b  (Raiatea  Island.  Society  Islands). 
adusta.  Partula.  1884,  JANSP,  (2)  9:79  [A  manuscript  name  in 

the  sjTionymy  of  Partula  varia  Broderip.] 
affinis.  Gibbida,  1872,  PCAS,  4:201.  (Viti  and  Samoa  Islands). 
affinis.    Nanina.    1887,    BSMF,    4:4    [nomen    nudum],    (Isle 

Faiwata,  Marquises  at  2000  feet).  [Is  Microcystis  subvenosa 

affims.  Rissoina.  1873.  PANSP,  p.  212,  pi.  2,  fig.  10  (Viti  Isles). 
affims.  Tomatellina.  1879,  PANSP,  p.  23.  [not  fig.]  (Rurutu 

Id.,  Austral  Islands). 
dbopmKtatm,  Goniobranchns.  1879.  PANSP,  p.  31.  (Huahine, 

Society  Islands).  [Is  Glossodoris  Ehrenberg  1831.] 
altemata.    Engina.    1872,    PCAS.    4:203.    (Samoa    and    Viti 

amanda.  Odostomia.  1873,  PANSP,  p.  225,  pi.  3,  fig.  47,  (Viti 

anceyana.  Pitys.   1887,  BSMF,  4:19,  (I.  le  Dominique,  Isles 

Marquises).  [F^tys  Beck  1837,  [nomen  nudum]  ],  is  Diaglyp- 

tus  Pilsbry  1893. 
angustivolata.  Microcystis.  1884.  JANSP,  (2)  9:20,  pi.  2,  fig.  34, 

a-b.  (Moorea  Island.  Society  Islands). 

98      THE  NAUTILUS 

April  23, 1979 

Vol.  93  (2-3) 

anthmciria.  Nassa,  1873,  PANSP,  p.  229.  pi.  3,  fig.  57,  (Viti 

(Ltsavaeturis,  Nanina.  1887,  PZS,  p.  169,  (Naviti  Island,  Assawa 

Group,  Viti  Islands). 
assimilis.   Mitra.    1873,   PZS,   p.   841    [not    fig.]    (Rarotonga, 

Samoa,  and  Viti  Islands). 
assimilL%  Trachomorpha.  1884,  JANSP,  (2)  9:27,  pi.  3,  fig.  44 

(Huahine  Island,  Society  Islands). 
avenacea.   Tnmcatella,    1887,   PZS.  p.  301   [not  fig.]  (Vanua 

Levu  [Island],  Viti  Islands). 
hiaihr.  Prirtula.  1884,  JANSP.  (2)  9:79,  [A  manuscript  name 

in  the  synonymy  oiPartula  varia  Broderip]. 
bicoUrr.    Tiimada.    1880,    JC.    3:38,    [not    fig.)    (Samoa   and 

Paumotu  Islands). 
boraborensts.  Pitys.  1884,  .JANSP,  (2)  9:32,  pi.  2,  fig.  18.  a-b, 

(Borabora  Island.  Society  Islands). 
bythineUaefirnnis.  Atmpis.  1884,  JANSP.  (2)  9:98.  pi.  3,  fig.  73, 

(Tahiti  and  Moorea  Islands,  Society  Islands). 
bythinaeformis.  "Mirussim"  Garrett,  Omphalotropis.  1887.  PZS, 
p.  310  [not   fig.]  (Vanua   Balavo,  Windward   Islands,  Viti 
caelata,  Oathurella,  1873,  PANSP,  p.  220.  pi.  Z  fig.  .34.  (Viti 

caelata,  Vitrinella,  1873,  PANSP,  p.  214,  pi.  2,  fig.  16,  (Kiva 

Island.  Viti  Isles). 
canalis,  Pitys.   1872,  AJC,  7:227.  pi.  19,  fig.   17,  (Rarotonga 

Island.  Cook's  Isles).  Lectotype  (by  Solem)  in  ANSP 477.52. 
cmtanea.  Turricula,  1880,  JC,  3:42,  [not  fig.]  (Samoa  and  Viti 

cavemula,  Pitys.  1872,  AJC,  7:226,  pi.  19,  fig.  16  (Rarotonga 
Id.,  Cook's  Isles  [Cook  Ids.] ).  [Tryon  had  changed  this  name 
to  Helix  mbcavemuLa  in  error  —  non  cavemula  Hombron 
and  Jacquinot  1841;  Garrett  had  described  his  species  in  the 
genus  Pitys  and  not  Helix.] 
cnmanguineiis,  Melampm.  1887.  PZS,  p.  287  [not  fig.]  (Vanua 

Levu  Island,  Viti  Islands). 
consubrina,  Pitys,   1884,  JANSP,  (2)  9:31,  pi.  2,  fig.  17.  a-c 

(Huahine  Island,  Society  Islands). 
consobrina,  Plecotrema,  1873.  PANSP,  p.  236,  pi.  3,  fig.  69, 

(Viti  Isles). 
ccmtigua.  Microcystis.  1887,  BSMF,  4:6  (lile  Dominique,  Isles 

costata,  Adf-nrhis,  1856  [1857],  PCANS,  1:103  (Hawaii  (Island], 

Hawaiian  Islands). 
costatogranosa,  Rissoim,    1873,  PANSP.  p.  211.  pi.  2.  fig.  7. 

(Viti  Islands). 
costulatum.   Caecum,   1873,   PZS,  p.  789.  (Kioa   Island.  Viti 

crassilabrum,  Rulimus.  1872,  AJC,  7:233,  pi.  18,  fig.  5,  (Vanua 

Levu  Id.  Viti  Isles). 
craxsilabrum.   Rissoa,    1856   [1857],   PCANS,   1:102   [not   fig.] 

(Hilo,  Hawaii  Id.,  Hawaiian  Islands). 
erebristriaXuii.  Melampus,  1887,  PZS,  p.  289  [not  fig.]  (north 

coast  of  Vanua  Levu  [Island],  Viti  Islands). 
erenilahrix.  Cheletrnpi,%  1873,  PANSP.  p.  215,  pi.  2,  fig.  18, 
(Paumotus  Islands).  [Tryon  puts  Cheletropis  in  the 
synonomy  of  Sinuxiijern  d'Orb.  are  pelagic  larvae  of  a 
marine  gastropod.  Garrett's  figure,  however,  does  not  show 
any  outer  lip  embayments.  [WJC]. 

cretacea.  Endndmta.  1884.  JANSP.  (2)  9:41.  pi.  2.  fig.  27,  a-b 

(Borabora  Island,  Society  Islands). 
crispa,  Mitra  (CosteUaria).   1872,  PCANS,  4:201  (Samoa  and 

Viti  Islands). 
crystallim,  Odostmnia.  1873,  PANSP,  p.  226,  pi.  a  fig.  49  (Viti 

crystallina,  ?Rissoa,  1873,  PANSP.  p.  216,  pi.  2.  fig.  24  (Kiva 

Island,  Viti  Isles). 
curta,  Chnphalotropis,  1879,  PANSP,  p.  28,  [not  fig.]  (Rurutu 

Id..  Austral  Islands). 
cuspidata,  Odustomia,  1873,  PANSP,  p.  228.  pi.  3.  fig.  54  (Viti 

daedalea.  Oathurella,  1873.  PANSP,  p.  219.  pi.  2.  fig.  .33  (Viti 

debilh  Rissoim,  1873,  PANSP.  p.  212,  pi.  2.  fig.  9  (Viti  Isles). 
decorticata,  Pitys,  1872,  AJC,  7:228.  pi.  19.  fig.  19  (Rarotonga 

Id.,   C<»k's   Isles.    [Cook    Ids.]).    Lectotj'pe   (by   Solem)    in 

ANSP  477.54. 
degagei.   Pttys,    1879,  PANSP.  p.   18   [not   fig.]   (Rurutu   Id.. 

Austral  Islands). 
degagei,  Succinea,  1879,  PANSP.  p.  26  [not  fig.]  (Rurutu  Id., 

Austral  Islands). 
denseco,stata,  Odostomia,  1873,  PANSP,  p.  223,  pi.  3,  fig.  42 

(Samoa  and  Viti  Isles). 
densestnata.  Odostomia.  1873,  PANSP,  p.  224,  pi.  3.  fig.  44 

(Viti  Isles  and  Samoa). 
discoidiae.  Microcystis.  1881,  JANSP,  (2)  8:409  [error  for  M. 

discordice  Garrett]. 
discorxiice.    Microcystis,    1881,   JANSP,    (2)    8:383    [not    fig.] 

(Cook's  Islands). 
ebumea,  Mitra,  1880,  JC,  3:15  [not  fig.]  (Paumotu  Islands). 
ebumostoma,    Mitra.    1880.    JC,    3:1.5.    [not    fig.]    (Paumotu 

erigua,  Murex.  1856  [1857],  PCANS,  1:102  [not  fig]  (Pure- 
shallow  P<x)ls:  on  the  rock>-  coasts  of  Hawaii). 
exqvidta,   Thahu    1872,  PCANS,  4:202   [not   fig.],   (Paumotu 

exquisita,  Mitra,   1872   [April   1893).  PZS.  p.  842   [not   fig.], 

(Paumotu,  Tahiti.  Cook's  Islands.  Samoa  and  Viti  Islands). 
eiilis,  Odostomia   1873,  PANSP.  p.  223,  pi.  3.  fig.  43  (Viti 

fenestrata.  FwsureUa  187a  PCANS,  4:'204  [not  fig.],  (Viti  and 

Samoa  Lslands). 

festiva,  Turricula  1880,  JC,  3:46  [not  fig.]  (Viti  klands). 

ficta  Endodfinta.  1884,  JANSP.  (2)  9:41  [Nomen  nudum, 
originally  listed  in  the  Schmeltz.  Cat.  Mus.  Godeffroy  5:223 
and  renamed  £!  cretacea  Garrett,  q.v.] 

filaris.  Cmdhanus,  1872,  PCANS,  4:202  [not  fig.],  (Samoa  and 

Viti  Islands). 
J}ericostata,  Turricula,  1880,  JC,  3:46  [not  fig]  (Paumotu  and 

Viti  Islands). 
foveolata.  PissureUa,  1872,  PCANS,  4:203  [not  fig.]  (Viti  and 

Samoa  Islands). 

'Pure  may  have  meant  Puna  but  the  word  in  Hawaii;ui  does  not 
mean  "shallow  pools".  Data  from  Dr.  Lee  Moettler  of  the  B.  P. 
Bishop  Museum. 

Vol.  93  (2-3) 

April  23,  1979 

THE  NAUTILUS      99 

fraiemda,  Mitra.  1872,  [April,  1873],  PZS,  p.  842  [not  fig.] 

(Tahiti,  Rarotonga,  Samoa  and  Viti  Islands). 
fiiscmigra,   Turricula,   1880,  JC,  3:47   [not  fig.]  (Kioa  shore 

reefs,  Viti  Islands). 
fitsifimnis.   Daphnella.    1873,   PANSP,   p.  229,   pi.  3,   fig.  58 

(Paumotus  Isles). 
gibbosa.    Engma.    1872,    PCANS,    4:203    (Viti    and    Samoa 

godeffroyana,  Nanina,  1872,  AJC,  7:223,  pi.  19,  fig.  9  (Interior 

of  the  N.  E.  part  of  Vanna  Levu,  Viti  Isles). 
geomeaensis.  Heiicina,   1893,  PANSP,   p.  233,   pi.  3,  fig.  63 

(Gomea  Island,  Viti  Isles). 
gracilis.  Rissoina.  1873,  PANSP,  p.  211.  pi.  2,  fig.  8  (Viti  and 

Society  Isles). 
granum.  Truncatella.  1872,  AJC,  7:225  [not  fig.]  (N.  E.  end  of 

Tavinni  Id.,  Viti  Isles). 
gregana.   Libera.    1884.  JANSP,   (2)   9:136,   pi.   2,   fig.   6,   a-b 

(Moorea  Island.  Society  Islands). 
guanensis.  Bulimus,  1872,  AJC,  7:235,  pi.  18,  fig.  8  (Guan  Isl., 

Viti  Isles). 
gummea.   Trochonanina,   1887,  BSMF,  4:14  (lile  Nuka-Hiva, 

lies  Marquesas). 
han-eyensis.  Pitys.  1872,  AJC,  7:228,  pi.  19,  fig.  20  (Rarotonga 

Id.,    Cook's    Isles    [Cook    Ids.]).    Lectotype    (by    Solem)   in 

ANSP  477.56. 
hirsuta.   Plecotrema.    1872,   AJC,  7:219,   pi.    19,   fig.  2   (Viti 

holosericea,  Neritina.  1872,  AJC,  7:219,  pi.  19,  fig.  1  (Vanna 

Lavu,  Viti  Islands). 
horrida.  Rissoina.   1873,  PANSP,  p.  210,  pi.  2,  fig.  5  (Viti 

hoyti.  Bulimus.  1872,  AJC,  7:234,  pi.  18,  fig.  7  (Vanna  Levu 

Id..  Viti  Isles). 
hoyti.  Nanina,  1872,  AJC,  7:221,  pi.  19,  fig.  6  (Tavinni  Id.,  Viti 

hoyti.  Tumcida,  1880,  JC,  3:47  [not  fig.]  (Viti  Islands). 
huaheinensis.  Partida,  1884,  JANSP,  (2)  9:78  [A  manuscript 

name  in  the  synonymy  ofPartula  varia  Broderip]. 
humeralis.   Mitra,    1880,   .JC,   3:18    [not    fig.]    (Anaa    Island, 

Paumotu  Islands). 
hyaixna.   missoa.   1873,  PANSP,  p.  217,  pi.  2,  fig.  25  (Samoa, 

Viti  and  Paumotus  Isles). 
hyaliniis.    Obeliscus.    1893,    PANSP,    p.    228,    pi.    3,    fig.    .56 

(Paumotus  and  Society  Isles). 
imperfirrata.  "Pease"  Garrett.  Partida.  1884,  JANSP,  (2)  9:.54, 

pi.  .3,  fig.  53  (Toloa  and  Hapai  Valleys,  west  coast  of  Raiatea 

[Island]  Society  Islands). 
indsa,  Tarricula,  1880.  JC,  3:63  [not  fig.]  (Kioa  shore  reefs, 

Viti  Islands). 
incisus.  Melampus.  1887,  PZS,  p.  289  [not  fig.]  (Vanua  Levu 

[Island]  Viti  Islands). 
iilfrastncta  Rissoa,  1873,  PANSP,  p.  215.  pi.  2,  fig.  21  (Kiva 

Island,  Viti  Isles). 
injrasulmta.  CMhurella.  1873,  PANSP,  p.  220,  pi.  2,  fig.  35 

(Viti  Isles). 
instricta,  Turricula,  1880,  JC,  3:48  [not  fig.]  (Viti  Islands). 
irregularis.  Patula,  1887,  PZS,  p.  179  [not  fig.]  (Viti  Levu,  Viti 

Islands).  Lectotype  (by  Solem)  in  BPBM  7982. 

kantavuenxis,  Trochomarpha,  1887,  PZS,  p.  177  [not  fig.]  (Kan- 

tava  Island,  Viti  Islands). 
kivaensis.  Nanina,  1873,  PANSP.  p.  237,  pi.  3,  fig.  71  (Kiva 

Island,  Viti  Lsles). 
koroensis.  Bulimus.  1872,  AJC,  7:236,  pi.  18,  fig.  9  (Koro  Isl., 

Viti  Isles). 
laeiicostata,   Tiirricula,    1880,  JC,  3:50   [not   fig.]   (Paumotu 

lamellwosta,  Patula,  1884,  JANSP,  (2)  9:30,  pi.  2,  fig.  11,  a-b 

(Tahiti  Island,  Society  Islands).  Lectotype  (by  Solem)  BPBM 

lento,  Microcysti'!,  1887,  BSMF,  4:5  (I.  le  Dominique,  I.  les 

laynrdiana.  Oniphalotropis.  1887,  PZS,  p.  310  [not  fig.]  (Vanua 

Balavo  [Mbalavu],  Windward  Islands  [Fiji  Islands] ). 
lentiginnsa.  Pythia,  1872,  AJC,  7:220,  pi.  19,  fig.  4  (Tavinni  Id. 

Viti  Isles). 
Libera  1881,  JANSP,  (2)  8:.390  [no  type  species  indicated]. 
liricincta,  Vitnnella.  1873,  PANSP,  p.  213,  pi.  2,  fig.  14  (Kiva 

Island,  Viti  Isles). 
littarinaeformis,  ?Rissoa  1873,  PANSP,  p.  215,  pi.  2,  fig.  18 

(Kiva  Island,  Viti  Isles). 
lutea,  Odostomia.  1873,  PANSP,  p.  226,  pi.  3,  fig.  .50  (Viti 

luteofusca,    Mitra,     1872    [1873],    PZS,    p.    842    [not    fig.] 

(Rarotonga,  Cook's  Islands). 
marquesana,  Pitys,  1887,  BSMF,  4:18  [not  fig.]  (Nuka-Hiva,  I. 

les  Marquesas). 
marqiiesana,   Suecirwa,    1887,   BSMF,   4::B7    [not    fig.]    (I.    le 

Dominique,  I.  les  Marqueses). 
maupiensis,   Pitys,    1872,    PCAS,   4:204    [not    fig.]    (Mautipi 

Island,  Society  Islands). 
maupiensis.  Pitys,  1873,  PANSP,  p.  233,  pi.  3,  fig.  64  (Maupiti 

Island,  Society  Isles). 
melanostoma,  Cithara,  1873,  PANSP,  p.  222,  pi.  2,  fig.  40  (Kiva 

Island,  Viti  Isles). 
rnelanostoma,  Persa.   1872,   AJC,  7:224,  pi.   19,  fig.  11   fV'iti 

merzianoides.  Helix  (Trochomarpha),  1872,  PANSP,  p.  237,  pi. 

3,  fig.  72  (Vanna  Levu  Island,  Viti  Isles). 
micans,  Tcimatellina.  1879,  PANSP,  p.  23  [not  fig.]  (Rurutu 

Id.,  Austral  Islands). 
milleciistata  Rissoina,  1873,  PANSP,  p.  210,  pi.  2,  fig.  3  (Viti 

mdlegrana   Daphnella,    1873,   PANSP,  p.  230,   pi.  3,   fig.  .59 

(Paumotus  Isles). 
miruyr,  Hipponix  (Amalthea).  1856  [18.57],  PCANS,  1:103  [not 

fig.]  (Hawaii  [Island],  Hawaiian  Islands). 
minutissima.  DriUia,  1873,  PANSP,  p.  218,  pi.  2,  fig.  .30  (Viti 

modicella,    Turricula,    1880,    JC,    3:53    [not    fig.]    (Paumotu 

monticola,  Heiicina,  1887,  BSMF,  4:42  (I.  le  Dominique,  I.  les 

Marqueses).  [Nomen  nudum,  \s  Heiicina  versihs  Ancey] 
mooreana,  Zonites,  1884,  JANSP,  (2)  9:23,  pi.  2,  fig.  28,  a-b 

(Moorea  Island,  Society  Islands). 
midticostata,   Rissoa,    1856   [1857],   PCANS,   1:103   [not   fig.] 

(Hilo,  Hawaii  Id.,  Hawaiian  Islands). 


April  23. 1979 

Vol.  93  (2-3) 

mulHlamMata.    Pitys.    1872.    AJC.    7:230.    pi.    19,    fig.    2.5 

(Rarotonpa  Id..  Cook's  Isles  [Cook  Ids]  ). 
muHUuieata,    Turbo.    18.56   [1857],   PCANS,    1:102.    [not    fit;.] 

(Hilo  Bay.  Hawaii  Id..  Hawaiian  Islands). 
multistriata,  \anina.  1887.  RSMF,  4:12  (I.  le  Taiwata.  I.  les 

Marqueses).  [Nomen  nudum] 
newcombittnum.  Succinea.  1^56  [1857].  PCANS.  1:103  [not  fig.] 

(Disctrict  of  Waimea  [Oahu  Id.]  Hawaiian  Islands). 
nigricans,  Turricula,  1880.  JC,  3:47  [Nomen  nudum,  is  Tur- 

riculafusconigra  Garrett.] 
nodosa.   Vitrinetla.   1873.  PANSP,  p.  214.  pi.  2.  fig.  17  (Viti 

obeliicus,  Odostomia.  1873.  PANSP,  p.  226,  pi.  3,  fig.  51  (Viti 

obesa.  Atropis.  1884,  JANSP,  (2)  9:99,  pi.  3.  fig.  72  (northwest 

part  of  Tahiti  [Island].  Society  Islands). 
obesa,  Claihimlla,   1873.  PANSP,  p.  221.  pi.  2.  fig.  ;36  (Viti 

ochrostnma,  Bulirmis.  1872.  AJC.  7:232.  pi.  18,  fig.  3  (Tavinni 

Island.  Viti  Islands). 
octolamellata.  Pttys.  1887,  BSMF,  4:18  [not  fig.]  (I.  le  Domini- 
que, I.  les  Marqueses). 
(rryza.  Odostomia,   1873,  PANSP,  p.  224,  pi.  3,  fig.  45  (Kiva 

Island,  Viti  Isles). 
oryza.  RissuiTia,  1873,  PANSP,  p.  210.  pi.  Z  fig.  4  (Kiva  Island. 

Viti  Islands). 
otareae.  Nanina,  1872,  AJC,  7:222,  pi.  19,  fig.  8  (Natawa  Bay, 

Vanna  Levu  [Fiji  Islands]). 
otareae.  Pitys.  1872,  AJC,  7:228,  pi.  19,  fig.  21  (Rarotonga  Id.. 

Cook's  Isles  [Cook  Ids.]  ).  Lectotype  (by  Solem)  ANSP  477.55. 
paliuiosu.%  Ophicardelus.  1872.  AJC,  7:220,  pi.  19,  fig.  3  (Viti 

papilla<<a.  [Mllia.   1873,  PANSP,  p.  218,  pi.  2,  fig.  29  (Viti 

paumotuensis.    Sciss^irella,     1873,    PZS.    p.    878    [not    fig.] 

(Paumotu  Islands). 
peaseana,  Tomatellina,   1884.  JANSP.  (2)  9:83.  pi.  2.  fig.  19 

(Moorea  Island.  Society  Islands). 
jjenseii,  Dirricnln.  1880..JC.3:.57  [not  fig.]  (Viti  Islands). 
periivata,  Pythm.  1872,  AJC,  7:221,  pi.  19,  fig.  5  (Viti  Isles). 
perpiexa.  Partida.  1884,  JANSP,  (2)  9:79.  [Nomen  nudum,  in 

the  synonymy  of  Partida  varia  Broderip,  in  Garrett.] 
perpiexa.  Tomatellina,  1879,  PANSP,  p.  24  [not  fig.]  (Rurutu 

Id.,  Austral  Islands). 
pieea,  Endodonta  fabrefacta  var.,  1884,  JA.NSP,  (2)  9:39,  [not 

fig.)  (W.  side  of  Raiatea  Island,  Society  Is  ands). 
picturata.  Nai-u-ella.  1872,  AJC,  7:224,  pi.  19,  fig.  13  (Vanna 

Levu,  Viti  Isles). 
pirujtm.  Ckithurella.  187.3,  PANSP,  p.  221,  pi.  2,  fig.  38  (Samoa 

and  Viti  Isles). 
pimjuix.  Partida.  1884,  JANSP,  (2)  9:77  [not  fig.]  (mountain 

ravines  at  the  head  of  Vaioara  Valley,  Raiatea  Id.,  Society 

Islands).  ["It  certainly  =  rustica"  [Garrett].  A  manascript 

name  in  the  synonymy  of  Partula  rustica  Pease.] 
planoconiut  'Mousson'  Garrett.  Trochomorpha,  1887.  PZS,  p. 
174  (Ono  Island,  Viti  Islands).  [This  was  a  ms.  name  by 
Mousson,  which  Garrett  described.] 
plano.fpira,  Patula.  JANSP.  (2)  8:388  [not  fig.]  (Rarotonga 
Island.  ('<K)k's  Islands).  Lectotype  (by  Solem)  in  Zool.  Mus. 
Univ.  Zurich. 

pfMiana.  Helicina.  1887.  PZS.  p.  313  [not  fig]  (Viti  Levu  [Fiji 

praj!ina.  Gibbxda,  187^  PCANS.  4:202  [not  fig.]  (Viti  Islands). 
proputqua.  Mitra,  1880.  JC.  3:22  [not  fig.]  (Society  Islands). 
propinqua.  Turricula,  1880.  JC.  3:58  [not  fig.]  (Viti  Islands). 
prorima,  Pitys.  1872.  AJC.  7:230.  pi.  19.  fig.  21  (Rarotonga  Id.. 

Cook's  Isles  [Cook  Ids]  ).  Lectotype  (by  Solem)  in  ANSP 

pulchra.  OdostomicL,  1873.  PANSP.  p.  225,  pi.  3,  fig.  48  (Viti 

pulchra.  Turricula.  1880,  JC,  3:56  [not  fig.]  (Viti  and  Samoa 

pidchella,  Clathurella,  1873,  PANSP,  p.  219,  pi.  2,  fig.  32  (Viti 

punctifera,  Clathurella,   1873,  PANSP,  p.  222,  pi.  2,  fig.  39 

(Society,  Samoa  and  Viti  Isles). 
punctifera.  Microcystis.  1879,  PANSP.  p.  17.  [not  fig.]  (Rurutu 

Id..  Austral  Islands). 
punctiperforata,  Pitys.  1884.  JANSP.  (2)  9:.32.  pi.  2,  fig.  16.  a-c 

(Moorea  Island.  Society  Islands). 
pura.  Microcystis.  1887.  BSMF.  4:5  [not  fig.]  (I.  le  Dominique. 

I.  les  Marqueses). 
pura.    Vitrinetla.   1873.  PANSP.  p.  213.  pi.  2.  fig.   13  (Kiva 

Island,  Viti  Isles). 
pusUla,  Drillia.  1873,  PANSP,  p.  219.  pi.  2.  fig.  31  (Viti  Isles, 

Cook's  Isles,  Paumotus  Isles). 
pygmaea.  Volvaria  (Volvarina),  1873,  PANSP,  p.  217,  pi.  2,  fig. 

27  (Viti  Isles). 
(juadricarinala,    Separatista,    1873,    PZS,    p.    878    [not    fig.] 

(Paumotu  Islands). 
rad>ata  Pease]  PaHnia,  1884,  JANSP,  (2)  9:74,  pi.  3.  fig.  45 

(Hamoa    Valley,    east    coast    of    Raiatea    Island,    Society 

raiatensis.  Helicina.  1884.  JANSP.  (2)  9:106.  pi.  .3.  fig.  69.  a-b 

(Raiatea  [Island].  Society  Islands). 
1-aiatensis.  Partula,  1884.  JANSP.  (2)  9:54.  [Nomen  nudum,  in 

the  synonymy  of  Partida  imperforata  "Pease"  Garrett .  q.v.] 
rambiensis.  Bulimus.  1872.  AJC.  7:233.  pi.  18.  fig.  4  (Rambi 

Id..  Viti  Isles). 
recedens.  Libera.  1884.  JANSP.  (2)  9:36.  pi.  2.  fig.  7  (Moorea 

Island.  Society  Islands). 
reticulata,  Pleurotoma  (Mangelia).  1856  [1857],  PCANS,  1:102 

[not  fig.]  (Hilo  Bay,  Hawaii,  Hawaiian  Islands). 
Rissopsis.  1873,  PANSP,  p.  228,  type  species  Rissopsis  typica 

Garrett,  (monotypic). 
rudi.'i.  Pitys.  1872.  AJC.  7:227.  pi.  19.  fig.  18  (Rarotonga  Id.. 

Cook's  isles  [Cook  Ids.]).  LectotjT)e  (by  Solem)  in  ANSP 

riigatus.  Bidiniiis.  1872.  AJC.  7:234.  pi.  18.  fig.  6  (Vanna  Levu 

ran(0«7i.s-i.s'.  Piitula.  1879,  PANSP,  p.  18  [not  fig.]  (Rurutu  Id.. 

Austral  Islands). 
riLsticus.  Melampii.':.  1887,  PZS.  p.  289  [not  fig.]  (Viti  Islands 

and  on  Tonga  and  Samoa  Islands). 
scaha,  Ri.osoma,  1873.  PANSP.  vol.  25.  p.  211.  pi.  2.  fig.  6  (Viti 

scatpta.  Microcystis.  1884.  JANSP.  (2)  9:21.  pi.  2.  fig.  30.  a-b 

(TahiiJi  Island.  Society  Islands). 
.^rhmeltziann,  Zoitites.   1887.  PZS.  p.  173  (Malolo  Island.  Viti 

Islands).  [Is  in  the  genus  (>rpiella.] 

Vol.  93  (2-3) 

April  23, 1979 


sa-ipta.   Bulla,    1856   [1857].   PCANS,   1:103   [not   fip.]   (Hilo. 

[Hawaii  Id.].  Hawaiian  Islands.) 
sculptili'!.  Rissmm.  1873,  PANSP,  p.  209,  pi.  2,  fig.  2  (Viti 

sculptUi.%  Vitrinella.  1873,  PANSP,  p.  214,  pi.  2,  fig.  15  (north 

coast  of  Natawa  Bay,  Vanna  Levu,  Viti  Isles). 
semilmeata.  Oathurcllu.  1873,  PANSP.  p.  221,  pi.  2,  fig.  37 

(Samoa  and  Viti  Isles). 
simidans.  Helicim.  1884,  JANSP,  (2)  9:105,  pi.  3.  fig.  66,  a-b 

(Tahiti  [Island],  Society  Islands). 
spiripuncta,  Mitra.  1880,  JC,  3:27  [not  fig.]  (Koro  reefs,  Viti 

steamseayia.  Microcystis.   1887,  PZS,  p.   171   [not   fig.]   (Viti 

stellaris.  Separatista,   1873,   PZS,  p.   879,   (Samoa   and   Viti 

striata.  Gibbida,  1872,  PCAS,  4:201  [not  fig.]  (Viti  and  Samoa 

striaiella.   Purpitra.    1856,    [1857],    PCANS.    1:102    [not    fig.] 

(Island  of  Hawaii.  Hawaiian  Islands). 
striatula,   Trochus.   (Mm-garita).    1856   [1857],   PCANS.   1:102 

(Hawaii  [Island]  Hawaiian  Islands). 
strict^is.  "Mousson"  Garrett.  Ostodes.  1887,  PZS,  p.  .306  [not 

fig.]  [See  Clench  1949,  B.  P.  Bishop  Museum,  Bull  196,  p.  21, 

fig.  (Holotype  8a)].  (Vatu  Lele  Island,  ex  museum  Godef- 

froy)  [Fiji  Islands.] 
subcomda.  Trockonanina,  1887,  BSMF.  4:13  (I.  le  Dominique,  I. 

subexcrescens.  Microcystis.  1881,  JANSP,  (2)  8:381,  (Rarotonga, 

Cook  Islands).  [Nomen  nudum.] 
sitbglobosa.  Succinea,    1884,   JANSP,   (2)  9:88,   pi.   2,   fig.   3 

(Tahiti  [Island]  Society  Islands). 
subghboxiis.  Pedipes.  1873,  PANSP,  p.  236,  pi.  3,  fig.  70  (Tan- 

thala  Island,  Viti  Isles). 
subntfa  "Pease"  Garrett.  Helicina,  1884,  JANSP,  (2)  9:104,  pi. 

3,   fig.   68,   a-b   (Raiatea   and   Borabora    [Islands]   Society 

subrugosa,  Trochmumina,  1884,  JANSP,  (2)  9:22,  pi.  2.  fig.  38, 

a-d  (Tahiti  and  Moorea  [Islands] ). 
subtexturata,  Mitra.  1880,  JC,  3:26  [not  fig.]  (Raiatea  Island, 

Society  Islands). 
subtilis.   Pitys.    1884,   JANSP,    (2)   9:31,    pi.   2,   fig.    15,   a-c 

(Huaheine  Island,  Society  Islands). 
s^dcata,  Odostomia.  1873,  PANSP,  p.  224,  pi.  3,  fig.  46  (Viti 

supracostata,  Rissoina,  1873,  PANSP,  p.  209,  pi.  2,  fig.  1  (Viti 

suturalis.  "Pease"  Garrett.  Partula,  1884,  JANSP,  (2)  9:6.3,  pi. 

3,  fig.  77  (Haamene  Valley,  east  coast  of  Tahaa   [Island], 

Society  Islands). 
tahitensis.  Mitra.  1880,  JC.  3:30  [not  fig.]  (Tahiti  Island,  Socie- 
ty Islands). 
tahitemis.  Trockonanina,  1884,  JANSP,  (2)  9:23,  pi.  2,  fig.  39, 

a-c  (Tahiti  Island,  Society  Islands). 
taneae.  Pitys.  1872,  PCAS,  4:204  [not  fig.]  (Maupiti  Island, 

Society  Islands). 
taneae.  Pitys.   1873,  PANSP,  p.  234,  pi.  3,  fig.  65  (Maupiti 

Island.  Society  Isles). 
tainnnietisis.  Helix.  1872,  AJC,  7:223.  pi.  19,  fig.  10  (Tavinni 

Id.,  Viti  Isles). 

tPtiella,  Nanina.  1872,  AJC,  7:222.  pi.  19,  fig.  7,  (Kioa  Id..  Viti 

tenuicostata,  Pitys,  1872,  AJC,  7:229.  pi.  19,  fig.  23  (Rarotonga 

Id.,  Cook's  Isles   [Cook's   Ids.]  ).   Lectotype   (by   Solem)  in 

terehra,  Rissoina.  1873,  PANSP,  p.  212,  pi.  2,  fig.  11  (Viti  and 

Samoa  Islands). 
tessellata,   Daphnella,    1873,   PANSP,   p.   .330,   pi.   3,   fig.  61 

(Paumotus  Isles). 
thdia,  Partida.  1884,  JANSP,  (2)  9:69,  pi.  .3,  fig.  46  (Huaru 

Valley,  west  coast  of  Raiatea  Island,  Society  Islands). 
themis.    Trcchomorpha.    1887,   PZS,   p.    177   (new   name   for 

Trochornorpha  ludersi  Mousson  1870,  non  Pfeiffer  18.55). 
trynni,  Goniodaris.  1873,  PANSP,  p.  2.32.  pi.  4  (Society  Islands). 
tntncata,  Rissoa.   1873,  PANSP,  p.  217.  pi.  2.  fig.  26  (Kiva 

Island,  Viti  Isles). 
tumuloides,  Pitys.  1872,  AJC,  7:225,  pi.  19,  fig.  15,  (Rarotonga 

Id..  Cook's  Isles  [Cook  Ids.]  ). 
turrita.  Plecotrema,  1873.  PANSP.  p.  235.  pi.  3,  fig.  68  (N.  E. 

end  of  Tavinni  [Taveuni  Island]  Viti  Isles). 
turrita.  Rissmrm.  1873,  PANSP,  p.  213,  pi.  2,  fig.  12  (Society 

typica,  Rissopsis.  1873,  PANSP,  p.  228,  pi.  3,  fig.  .55  (Viti  and 

Samoa  Isles). 
unilamellata,    Pitys.    1873,    PANSP,    p.    235.    pi.    3.    fig.   67 

(Rarotonga  Island,  Cook's  Isles). 
unilineata.  Odostomia.  1873,  PANSP,  p.  227,  pi.  3,  fig.  .53  (Viti 

unilineata,  Turricula,  1880,  JC,  3:60  [not  fig.]  (Viti  Islands). 
ventricosa.  Turricula,  1880,  JC,  3:55  [not  fig.]  (Samoa  and  Viti 

Islands),  [Nomen  nudum].  [Is  T  porphyretica  Reeve.] 
venusta,  Rissoa,  1873,  PANSP,  p.  216,  pi.  2,  fig.  23  (Viti  Isles). 
vidmUndes.  Drillm.  1873,  PANSP,  p.  217,  pi.  2,  fig.  28,  (Viti 

riolacea.  Thala.  1872,  PCAS,  4:202  (Samoa  and  Viti  Islands). 
virginea,  "Pease"  Garrett,  Partula,  1884,  JANSP,  (2)  9:61,  pi. 

3,  fig.  54  (Vaipiti  Valley,  west  coast  of  Tahaa  [Island]  Socie- 
ty Islands). 
vitiarm,  Paludinella,   1872,  AJC,  7:224.  pi.   19,  fig.   12  (Viti 

vitiense.  Caecum,  1873,  PZS,  p.  879  (Kioa  Island,  Viti  Islands). 
vitiensis.  Assiminea.   1872,  AJC,  7:'225,  pi.   19,  fig.  14  (Viti 

intiensis,  Placostylus,  1887,  PZS,  p.  184   [not  fig.]  (Na  Viti 

Levu  Bay,  N.  E  coast  of  Viti  Levu,  Viti  Islands). 
litiemis.  Pupina.  1873,  PANSP,  p.  233,  pi.  3,  fig.  62  (Gomea 

Island,  Viti  Isles). 
ritrea.    Daphnella,    1873,    PANSP,    p.    230,    pi.    3,    fig.    60 

(Paumotus  Isles). 
vitrea,  Odostomia.  1873,  PANSP,  p.  227,  pi.  3,  fig.  52  (Viti 

ritrea.  ?Ri%'ioa.  1873,  PANSP,  p.  215,  pi.  2,  fig.  19  (Kiva  Island, 

Viti  Isles). 
woapoensis,  Pitys,  1887,  BSMF,  4:17,  (1.  le  Woapo,  I.  les  Mar- 

youngi,  Pitys,  1872,  AJC,  7:229,  pi.  19,  fig.  22  (Rarotonga  Id., 

Cook's  Isles  [Cook  Ids.]  ).  Lectotype  (by  Solem)  in  ANSP 

zebra.  Strigatella.  1880.  JC.  3:35  [not  fig.]  (Viti  and  Samoa 



April  23, 1979 

Vol.  93  (2) 

zehrina.  Mitra.  1872  [187.3]  PZS.  p.  »42,  [not  fig.]  (Paumotu. 

Tahiti.  Cook's  [Islands],  Samoa.  Viti  Islands). 
zebrina.  Pitys.  1873.  PANSP,  p.  234,  pi.  .3.  fig.  66  (Rarotonga 

Island.  Cook's  Isles). 

Additional  Names  by  William  Harper  Pease 

These  names  were  inadvertently  omitted  by  W. 
J.  Clench  (1975),  Nemouria,  no.  16,  Delaware 
JMaseum  of  Natural  History. 

apprurinintn  Pease.  PiiriuUu  1884,  .JANSP,  (2)  9:7.5  [nomen 
nudum].  [Is  P.  inttata  It  was  listed  earlier  by  Glo>Tie 
in  the  Journal  of  Conchology.  1:338.  May.  1878]. 

microsUima  Pease,  Partida.  1884,  JANSP,  (2)  9:74  [nomen 
nudum].  [Is  P.  radiata  "Pease"  Garrett,  lyr] 

fraterntld  Pease,  Helix,  1867,  AJC,  3:104.  [New  name  for 
Helix  sadptilis  Pease,  18&5,  non  Bland  1858.] 

oimlaiifiixis  ""  Tryon.  Milmiiu.  18«i.  A.JC.  2:299.  pi.  2f), 
fig.  4  (Oualan  I.  [now  Kusaie  Island.  Caroline  Islands.]).  [A 
manuscript  name  by  Pease  but  never  described  by  him.] 

IMoIluscan  Bibliography  of  Andrew  Garrett 

1856  [1857]  "On  New  Species  of  Marine  Shells  of  the  Sand- 
wich Islands."  Pmc.  California  Acad.  Nat.  Sci..  1:102-103. 

1872  a.  "Descriptions  of  New  Species  of  Shells  from  the  South 
Sea  Islands."  Pmc.  California  Acad.  Sci.,  4:'201-204. 

1872  b.  "Descriptions  of  New  Species  of  Land  and  Freshwater 
Shells." ^IniCT-.  J.  Conch.,  7:219-230.  pi.  19. 

1872  c.  "List  of  Species  of  Bulimus  Inhabiting  the  Vili 
Islands,  with  Notes  on  Their  Geographical  Range,  and 
Descriptions  of  New  Species."  Amer.  J.  Conch.  7:231-236,  pi. 

1873  a.  "Descriptions  of  New  Species  of  Marine  Shells  In- 
habiting the  South  Sea  Islands."  Proc.  Acad.  Nat.  Sci. 
Philadelphia,  pp.  •2(J9-231.  pi. 2-3. 

1873  b.  "Description  of  a  New  Species  of  Goniodoris."  Proc. 
Acad.  Nat.  Sci.  Philadelphia,  p. 232,  pi.  4. 

1872  [1873  c]  "List  of  the  Species  of  Mitridae  Collected  at 
Rarotonga,  Cook's  Islands,  with  Notes,  also  with  Descrip- 
tions of  New  Species."  Pmc.  Zool.  Soc.  London,  pp.  839-843. 

1873  d.  "Description  of  New  Species  of  Land  Shells  Inhabiting 
the  South  Sea  Islands."  Pmc.  Acad.  Nat.  Sci.  Philadelphia, 
pp.  233-237,  pi, 3. 

1872  [1873  e.]  "Description  of  a  New  Species  of  Scissurella 

from   the  Paumotu   Islands."  Proc.  Zool.  Soc.  London,   pp. 

1872  [1873  f.]  "Descriptions  of  Two  New  Species  of  Caecum 

from  the  Viti  Islands."  Pmc.  Zool.  Soc.  London,  p.  879. 
1872  [1873    g.]     "Descriptions     of    Two     New     Species     of 

Separatista."   Pmc.   Zml.   Soc.   Limdon.   p.   878    [Paumotu 

1878     a.  "Occurrence     of     Gadinia     reticulata     Sow.,     in 

Southeastern  Polynesia."./,  of  Conch.  1:335. 

1878  b.  "Occurrence  of  Crepidula  aeuleata  Gmel.,  in  the  Mar- 
queses  Islands."  J  of  Conch.  1:335-336. 

1878  c.  "Annotated  Catalogue  of  the  Species  of  Conus  Col- 
lected in  the  South  Sea  Islands."  J.  of  Conch.  l:3,53-.367. 

1879  a.  "List  of  I.and  Shells  Inhabiting  Rurutu.  one  of  the 
Austral  Islands,  [Tabuai  Ids.]  with  Remarks  on  Their 
Synonymy,  Geographical  Range  and  Descriptions  of  New 
Species."  Proc.  Acad.  Nat.  Sci.  Philadelphia,  pp.  17-30,  [pp. 
17-24,  March  25, 1879;  pp.  25-30,  April  15, 1879]. 

1879  b.  "Description  of  a  New  Species  of  Goniobranchus." 
Proc.  Acad.  Nat.  Sci.  Philadelphia,  p.  31. 

1879  c.  "Annotated  Catalogue  of  the  Species  of  Cypraeidae 
Collected  in  the  S.  Sea  Islands."./  of  Conch.,  2:105-128. 

1880  "Catalogue  of  the  Polynesian  Mitridae,  with  Remarks  on 
Their  Geographical  Range,  Station  and  Descriptions  of  Sup- 
posed New  Species."  J.  of  Conch..  3:1-7.3,  [pp.  1-32,  Jan. 
1880;  pp.  33-73,  April  1880]. 

1881  "The  Terrestrial  Mollusca  Inhabiting  the  Cook's  or 
Hervey  Islands."  Jour.  Acad.  Nai.  Sci.  Philadelphia,  (2) 

1884  "The     Terrestrial     Mollusca     Inhabiting     the     Society 

Islands."  .Jcmr.  Acad.  Nat.  Sri.  Philadelphia,  (2)  9:17-114,  pi. 

1887  a.  "On  the  Terrestrial  Mollusks  of  the  Viti  Islands.  Part 

I."  Proc  Zool.  Soc.  London,  pp.  164-189  [June  1, 1887]. 
1887  b.  "Mollusques  Terrestres  des  lies  Marquises."  Bull.  Soc. 

Maine.  France,  4:1-48. 
1887  c.  "On  the  Terrestrial  Mollusks  of  the  Viti  Islands,  Part 

II."  Proc.  Zool.  Soc.  London,  pp.  284-316  [Aug.  1. 1887]. 
1887  d.  "The  Terrestrial  Mollusca  Inhabiting  the  Samoa  or 

Navigator    Islands."   Proc.   Acad.   Not.   Sri.   PhiUidelphia, 



I  wish  to  thank  Mr.  Edwin  H.  Bryan  for  data 
on  place  names  and  for  the  history  on  the  Andrew 
Garrett  Collection  and  to  Danielle  B.  Fellows  for 
the  chronological  data  on  the  collection.  To  Dr. 
Yoshio  Kondo  for  xerox  copies  about  Andrew  Gar- 
rett held  in  the  library  of  the  Bemice  B.  Bishop 
Museum.  To  Mary  Anne  Quilty,  I  am  most  grate- 
ful for  typing  the  manuscript  and  for  several  help- 
ful suggestions. 

My  thanks  are  due  to  Dr.  Joseph  Rosewater  of 
the  National  Museum  of  Natural  History  for 
checking  the  publications  of  Andrew  Garrett  in 
the  department  of  Mollusks. 

Vol.  93  (2-3) 

April  23, 1979 



Hugh  J.  Mitchell-Tapping' 

Department  of  Geology 

The  Florida  State  University 

Tallahassee,  Florida  32306 


Eleven  shallow-icater  species  of  C-decum,  from  the  marine  sediment  aronnd  Water 
Island,  are  described  according  to  their  microsculpture  as  observed  under  the  scan- 
ning electron  microscope.  One  new  species,  Caecum  donmoorei.  irhich  was  found  in 
Sprat  Bay.  Water  Island.  ?.s  also  described. 

In  1973,  a  study  was  made  of  the  shallow  ma- 
rine carbonate  sediment  around  Water  Island, 
the  fourth  largest  island  in  the  U.  S.  Virgin  Is- 
lands group.  A  total  of  56  samples  of  approxi- 
mately 100  grams  each  was  collected  around  the 
island  at  sites  which  were  exposed  to  differing 
amounts  of  wave-energy.  A  total  of  618  Caecidae 
was  picked  from  the  samples  and  their  distribu- 
tion around  the  island  was  plotted  according  to 
the  number  of  specimens  found  (Fig.  1). 


St.  Thomas 




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FIG.  la.  Ih.stnbutiim  of  the  number  of  xpeciiiienn  collected 
around  Water  Island,  U.  S.  Virgin  Island-t.  Stippled  areas  are 
grassbed,  low  wave-energy  areas. 


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'Present  address:  6101  Warwick  Qiurt,  New  Orleans,  La  70114. 

FIGS.  1-8.  1,  C.  breve  Foliii  Xlo:  2,  C.  breve  Folin  X120: 
3,  C.  imbrieatum  Cm-penter  X15;  4,  C.  imbricatum  Carpenter 
X120;  5,  C.  tenuicostatum  Folin  X^O;  6,  C.  tenuicostatum 
Folin  X215;  7,  C.  tenuicostatum  Folin  X1.5;  8,  C.  tenuicosta- 
tum Folin  XUO. 

Compared  with  samples  from  Bahia  Honda 
in  the  Florida  Keys,  where  up  to  212  specimens 
per  sample  occur,  there  are  few  specimens  in  this 
area.  This  may  be  due  to  the  geographical  loca- 
tion of  the  Virgin  Islands  and  the  prevailing  east- 
west  current.  This  current  results  in  the  speci- 
mens being  representative  of  the  local  standing 
crop  only.  It  is  interesting  to  note  that  not  a  sin- 
gle specimen  of  Caecum  in.sulanon  Moore,  origin- 
ally found  on  the  sister  island  of  St.  John  (Moore, 
1970),  was  present  in  Water  Island  samples. 


April  23. 1979 

Vol.  93  (2-3) 


4 ^^^^^^^^^^^v     i^l^^^^^^^^^H 


FIGS.  9-16.  9,  C.  regulare  Carpenter  X25:  10,  C.  regulare 
Carpenter  X175:  11,  C.  textile  Fniin  Xii5:  12,  C.  textile  Folin 
XSiO;  13,  C.  cornucopiae  Carpenter  X15;  14,  C.  comucopiae 
Carpenter  X2i0;  15,  C.  gurgulio  Carpenter  X20:  16,  C.  gur- 
gulio  Carpenter  X160. 

The  distribution  of  the  618  specimens  (Fig.  1) 
shows  no  discriminate  pattern,  other  than  the 
low  count  for  the  eastern  side  of  the  island.  This 
small  number  of  specimens  might  be  attributed 
to  the  local  water  current  through  Gregerie 
Channel,  which  would  move  the  specimens  to  a 
lower  energy  area.  The  dominant  species  in  the 
grass-beds,  low-energy  areas,  were  Caecum  comu- 
copiae Carpenter  (Figs.  13  and  14)  and  C.  mtidum 
Stimpson.  Distinguishing  between  these  two 
species  is  rather  difficult,  but  C.  nitidum  tends 
to  be  larger  with  a  more  oblique  aperture  in  the 
adult  stage.  The  row  of  dark  spots  sometimes 
seen  on  C.  comucopiae  by  Moore  (1972)  was  not 
apparent  in  the  specimens  from  the  grassbeds 
and  only  seen  on  two  specimens  from  a  reef  area 
in  a  southside  bay.  In  the  reef,  or  medium  wave- 
energy  areas,  the  most  abundant  species  was 
C.  regulare  Carpenter  (Figs.  25,  26,  27  and  28). 
C.  breve  Folin  (Figs.  1  and  2),  C.  lineicinctum 
Folin  (Figs.  31  and  32),  and  C.  floHdanvm  Stimp- 
son (Figs.  19  and  20)  were  also  found  in  these 
areas.  The  dominant  species  in  the  rocky,  high 
wave-energy  areas  on  the  southern  side  of  the 

island  was  C.  imbricatum  Carpenter  (Figs.  3  and 
4).  A  rare  species,  C.  tenuicostatum  Folin  (Figs. 
5,  6,  7,  8,  23  and  24)  was  also  found  in  these 
areas.  Some  of  the  specimens  of  C.  tenuicostatum 
appear  under  the  SEM  to  have  longitudinal  ribs 
which  are  smoother  and  less  raised  on  one  side, 
giving  an  appearance  of  wavelike  ribs  moving 
clockwise  looking  down  from  the  aperture. 

One  species  common  to  all  areas  is  C.  textile 
Folin  (Figs.  11  and  12).  Some  specimens  of  C. 
textile  (Figs.  17  and  18)  appear  under  the  light 
microsc-ope  as  having  a  raised  interspace  between 
the  annular  ridges,  giving  an  almost  smooth  ap- 
pearance, while  the  SEM  reveals  that  the  longitu- 
dinal striae  on  the  ridges  are  continued  through 
the  interspace  and  are  joined  to  those  on  the 
adjacent  ridges  (Fig.  18).  Another  species,  also 
common  to  all  wave-energ>'  environments,  is  C. 
regulare  Carpenter  and  its  close  relative,  C. 
gurgulio  Carpenter  (Figs.  15  and  16).  The  sculp- 
ture of  C.  regulare,  as  revealed  by  the  SEM, 
shows  an  absence  of  striae  between  the  well- 
raised,  flat-topped  annular  ridges  (Fig.  26).  This 
can  also  be  seen  in  the  specimen  described  by 

FIC.S.  17-24.  17,  C.  textile  Fo/i«  X.W,  18,  C.  textile /-"o/ih  X^IO; 
19,  C.  floridanum  Stimiison  X20:  20,  C.  floridanum  Stimpsmt 
X1J,'>:  21,  C.  (iimnicKirei  h.s.  jximlinx'  XW:  22,  C.  donmoorei 
n.x.  iximtifiH'  X1.',(K  23,  ('.  tenuicxistatum  FuUn  Second  xtage 
XJO:  24,  C.  tenuicostatum  Falin  X«ft 


April  23, 1979 


FIGS.  25-:32.  25,  C.  regulare  Cm-pent er  XIO;  26,  C.  regulare 
Carpetiter  X210:  27,  C.  regulare  Carpenter  Second  staye  plus 
part  of  third  staye  XJS:  28,  C.  regulare  Carpenter  X175: 
29,  C.  donirnwrei  n.s.  Imlotyije  X20:  30,  C.  donmoorei  n.s.  ho- 
kitifiw  Xl'O;  31,  C.  lineicinctum  Folin  X20:  32,  C.  linei- 
cinctum  Folin  XSO. 

Moore  (1972).  C.  gurgulio  is  very  similar  in  ap- 
pearance, but  is  smaller,  has  less  curvature,  and 
low,  flat-topped,  closely  set  ribbing  with  striae 
present  only  between  the  ribs  (Fig.  16). 

Caecum  donmoorei,  n.  sp. 

DescriTption:  Shell  tapered  with  slight  curva- 
ture; 27  annular  ribs  well-spaced,  raised, 
rounded-topped  (Fig.  31);  primary  striae  in  inter- 
space thick;  secondary  striae  thin;  all  striae  con- 
tinue over  surface  of  ribs  (Fig.  32);  Septum 
slightly  convex,  bearing  broad,  weak  mucro 
angled  to  right;  two  small  circular  ribs  around 
circular  aperture;  no  varix;  color  white  in  holo- 
type,  some  specimens  tinged  brovm  near  aper- 
ture; length  1.4  mm. 

Remarks:  This  species  has  round-topped  and 
striated  ribs  as  opposed  to  the  smooth,  flat -topped 
ribs  of  C.  regulare.  It  differs  from  C.  giuyulio 
which  has  rounded,  robust,  but  not  so  raised,  ribs 

which  are  small,  smooth,  and  bear  no  striae. 
There  is  also  no  similarity  to  C.  toniatum  Verrill 
and  Bush  which  has  strong  ribs  and  a  very  strong 
mucro  and  appears  to  be  confined  to  Bermuda. 
The  most  distinguishing  feature  of  C.  donmoorei 
which  appears  to  justify  the  naming  of  a  new 
species,  is  the  round-topped  striae-covered  ribs. 
This  species  is  named  after  Dr.  D.  R.  Moore,  a 
leader  in  the  field  of  the  study  of  the  Caecidae. 

Tijpe -locality:  Holotype:  In  5  m  of  water  in 
Sprat  Bay,  Water  Island,  USVI.  Four  paratypes 
were  found  in  Ruyter  Bay  and  Elephant  Bay  at 
similar  water  depths  and  of  low  wave-energy. 

Ti/pen:  Holotype  deposited  in  1977  in  the  Dela- 
ware Museum  of  Natural  History  #119521.  Para- 
types were  placed  in  the  collection  at  the  Florida 
Bureau  of  Geology,  Tallahassee,  #12909. 


I  am  grateful  directly  to  Dr.  J.  R.  Taylor  for 
allowing  the  examination  of  the  collection  held  at 
the  British  Museum  of  Natural  History  in  Lon- 
don, and  indirectly  to  Dr.  D.  R.  Moore  for  his 
work  of  classifying  some  of  this  collection.  I  am 
also  grateful  to  Philip  Dawson  of  St.  Thomas  for 
his  aid  in  the  collection  of  the  samples,  and  to 
Dr.  S.  W.  Wise  and  Dr.  R.  Wright  of  the  Depart- 
ment of  Geology  of  The  Florida  State  University, 
Tallahassee,  and  Dr.  D.  R.  Moore,  University  of 
Miami,  Miami,  for  their  reading  and  criticism  of 
the  manuscript.  Scanning  electron  micrographs 
were  taken  on  an  ISI  Supermini  I,  housed  in  the 
Department  of  Geology  at  The  Florida  State 
University.  Support  in  part  was  provided  by  NSF 
grant  #121-323-210. 


Moore,  D.  R.  1969.  A  new  Caecum  from  the  tropical  Western 
Atlantic.  TheNautilm  83(l):26-28. 

.  1970.  A  new  Caecum  from  Puerto  Rico  and  the  Vir- 
gin Islands.  Bull.  Mar.  Sn.  20(2):368-373. 

.  1972.  Ecological  and  systematic  notes  on  Caecidae 

from  St.  Croix.  U.  S.  Virgin  Islands.  Buil.  Mar.  Sci.  22(4): 

Weber,  J.  A.  1961.  Marine  shells  of  Water  Island,  Virgin  Is. 
The  Nautilus  75(2):55-60. 


April  23. 1979 

Vol.  93  (2-3) 


Donald  R.  Moore 

University  of  Miami  Rosenstiel  School  of 

Marine  and  Atmosphere  Science 

Miami,  Florida  33149 

Mabel  Fentress  Miller 

and        Environmental  Education  Propram, 

Science  Education  Dept. 

Dade  County  Public  Schools 

1410  Northeast  Second  Avenue 

Miami,  Florida  33132 

The  first  living  bivalved  gastropod  was  observed 
by  Kawaguti  just  twenty  years  ago  (Kawaguti 
and  Baba,  1959).  A  year  later,  in  October  1900, 
Kawaguti  visited  Miami  in  an  effort  to  find  these 
animals  in  the  western  Atlantic.  He  was  unsuc- 
cessful, but  shortly  after  Edmunds  (1962)  re- 
ported a  species  from  Jamaica.  This  species  was 
described  as  Berthelinia  caribbea  Edmunds,  1963. 
B.  canbbea  was  reported  from  Puerto  Rico  by 
Warmke  (1966),  and  later  from  Panama  and 
Brazil  (Meeder  and  Moore,  1972). 

The  search  for  B.  caribbea  in  United  States 
waters  was  unsuccessful  for  many  years;  then 
one  of  us  (MFM)  collected  eight  live  specimens  in 
the  Florida  Keys  on  14  July  1978.  They  were 
collected  in  sea  wall  scrapings  from  a  canal  off 
Tavernier  Creek,  Plantation  Key.  After  being 
observed  alive,  they  were  preserved  in  alcohol. 
Four  of  these  were  donated  to  the  School  of  Marine 
Science,  University  of  Miami. 

This  is  the  first  living  species  of  the  family 
Juliidae  to  be  reported  from  Florida.  A  fossil 
species,  Julia  Jloridana  Dall,  1898,  was  described 
(as  a  pelecypod)  from  the  Oligocene  of  north- 
western Florida  along  the  Chipola  River.  The 
genus  Julia  is  presently  found  living  in  the  cen- 

tral and  western  Indo-Pacific,  and  is  known  from 
two  fossil  species  in  the  western  Atlantic  area. 
Berthelinia  caribbea  is  not  likely  to  be  found  as 
a  fossil,  however,  as  it  is  extremely  thin-shelled. 

B.  caribbea  is  now  known  from  the  Florida 
Keys,  Jamaica,  Puerto  Rico.  Panama,  and  Brazil. 
It  appears  to  have  plankton ic  larvae,  and  should 
be  found  at  many  more  localities  in  the  Tropical 


Dall.  W.  H.  1898.  Contributions  to  the  Tertiary  fauna  of  Flor- 
ida. Trans.  Wagner  Free  Inst.  Sci.  Philad.  3(4):.571-947. 
pis.  23-.i5. 

Edmunds.  M.  1962.  Bivalve  gastropod  from  .Jamaica.  Nature, 

.  196.3.  Berthelima  raribben  n.  sp..  a  bivalved  gas- 
tropod from  the  west  Atlantic.  .1.  Linn.  Soc.  London 
44(9)2):  7.31 -7.39,  pi.  1. 

Kawaguti.  S.  and  K.  Baba.  19.59.  A  preliminary  note  on  a  two- 
valved  sacoglossan  gastropod.  Tamanuvalva  limar.  n.  gen., 
n.  sp.,  from  Tamano.  .Japan.  Biol.  .J.  Okayama  Univ.  6(3-4): 
177-184. 10  figs. 

Meeder.  .1.  F.  and  D.  R.  Moore.  1972.  The  extension  of  range  of 
RcrthrUiua  mnhhea  Edmunds  to  Brazil  and  Panama  (Mol- 
lusca.  (lastropoda).  Carib.  Jmir.  Sci.  11(3-4):1.")9-161. 

Warmke.  G.  1966.  Two  species  of  the  bivalved  gastropod  Berthe- 
linia found  in  Puerto  Rico.  The  Nautilus  79(4):1.39-141. 

This  issue  of  \'ol.  9:^  cnnibines  numbers  2  and  3.  Numbei-  1  will  h'  published  in  October.  1979. 


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Volume  94,  number  4  —  October  30, 1979 



Donald  M.  Allen 

Bioldgical  aspects  of  the  Calico  Scallop.  Argopecten  Gibbu.%  determined  by  Spat  Monitoring 107 

Francis  R.  Home  and  Steve  Mcintosh 

Factors  influencingdistribution  of  Mussels  in  the  Blanco  Riverof  Central  Texas 119 

Miguel  A.  Klappenbach 

Allocation  of  "Mnryinclln  "Cordrroi  Carcelles,  1953  to  a  New  Genus  in  the 

Volute  Subfamily  Odontocymbiolinae  (Gastropoda) 133 

Alex  S.  Tompa 

Localized  egg  shell  dissolution  during  development  in  Stenotrema  Leai 

(Pulmonata:  Polygyridae) 136 

Arthur  H.  Clarke 

Gastropods  as  indicators  of  Trophic  Lake  Stages 138 

Leslie  Hubricht 

A  New  Species  of  Amwico/a  from  an  Arkansas  Cave  (Hydrobiidaoe)  142 

K.  Elaine  Hoagland 

The  Behavior  of  Three  Sympatric  Species  of  Orpiduln 

(Gastropoda:  Pi'osobranchia)  from  the  Atlantic,  with  implications  for  Evolutionary  Ecology  ....  143 
John  J.  Jenkinson 

Tlie  Occurrence  and  Spread  of  Corbicula  Manilensis  in  East -Central  Alabama 149 

Archie  L.  Jones 

Descriptionsof  Six  New  Forms  of  Florida  Tree  Snails,  LM7?iusFa.sCTa<2i.s 153 

R.  Tucker  Abbott  and  C.  John  Finlay 

Oiicdrnii^  Gismnni.  a  New  Muricid  Gastropod  from  the  West  Indies 159 

Susan  B.  Gallagher  and  George  K.  Reid 

Population  Dynamics  and  Zonation  in  the  Periwinkle  Snail,  Littorina  Angulfera. 

of  the  Tampa  Bay,  Florida,  Region 162 

Arthur  H.  Clarke 

Sphaeriidae  as  indicators  of  Trophic  Lake  Stages 178 

A.  Omura.  W.  K.  Emerson  and  T.  L.  Ku 

Uranium  -  Series  Ages  of  Echinoids  and  C«rals  from  the  Upper  Pleistocene 

Magdalena  Terrace,  Baja  California  Sur,  Mexico 184 

Walter  E.  Klippel  and  Paul  W.  Parmalee 

The  Naiad  Fauna  of  Lake  Springfield,  Illinois:  an  Assessment  after  Two  Decades 189 

Publications  Received ii 


Leathern.  Wayne  and  Don  Maurer.  1979.  (Revised  edition  of) 
Phylum  Mollusca:  A  Guide  to  the  Mollusca  of  Delaware 
Bay  Region.  42  mimeographed  pp.  A  key  to  the  known 
species.  $3.00.  Publications,  C.M.S.,  Univ.  Delaware.  Newark, 
DE  19711. 

Gibson-Smith.  J.  and  W.  1979.  The  Genus  Arcinella  (Mollusca: 
Bivalvia)  in  Venezuela  and  Some  Associated  Faunas.  Geos 
no.  24:  11-32,  3  pis.  A.  jungi  and  A.  candelariana  n.  spp.. 
and  Nicotia  n.  subgenus  (type:  Chama  draconis  Dall)  from 
the  Miocene  are  described.  Purpura  weisbordi  n.  sp.  is  what 
Weisbord.  1962.  called  P.  patula  Linnaeus.  Many  of 
Weisbird'.s  1962 species  are  sv-nonymized. 

Menzel,  R.  W.  1974.  Portuguese  and  Japanese  Oysters  are  the 
Same  Species.  Jour.  Fish  Research  Bd.  Canada  31(4): 
45:3-456.  The  author  suggests,  on  biological  evidence,  that 
Crassostrea  angidata  Lamarck  (1819)  from  Portugal  be  con- 
sidered a  subspecies  of  C.  gigas  (Thunberg.  1793)  from 
Japan,  the  latter  possibly  having  been  introduced  from  Por- 

Purchon,  R.  D.  1978.  An  Analytical  Approach  to  a  Classifica- 
tion of  the  Bivalvia.  Phil.  Trans.  Royal  Soc.  London.  B.  284: 

/(  Naturalkla  Siciliano.  vol.  1  and  2  (1977-78).  A  new  quarter- 
ly containing  several  scientific  papers  on  mollusks.  Instituto 
di  Zool.  della  Univ.,  18  Via  Archirafi,  Palermo,  Italy  90123. 

Eyster.  Linda  S.  1979.  Reproduction  and  Developmental 
Variability  in  the  Opisthobranch,  Tenellia  pallida.  Marine 
Biology,  vol.  51,  pp.  1,3;V140.  Pelagic  and  non-pelagic  develop- 
ment occurs  within  single  population. 

Ti-yonia,  no.  1.  Catalog  of  the  Chiton  T>T)es  of  the  Academy  of 
Natural  Sciences  of  Philadelphia.  By  G.  M.  Davis.  R. 
Robertson  and  M.  Miller.  .56  pp.,  mimeographed.  .$7.00. 
Miscellaneous  publication  of  the  Dept.  Malacology-,  Acad. 
Nat.  Sci.  Phila..  Phila..  PA  19103.  Lists  primary  t.vpes  and 
syntypes.  with  complete  data,  and  by  geographical  areas. 

Jaume,  Miguel  L.  and  Alfredo  de  la  Torre.  1976.  Los  Urocop- 
tidae  de  Cuba  (  -  Pulmonata).  Cieticias  Biological 
(Habana).  no.  .53,  122  pp.  Contains  numerous  new  genera 
and  specie.s.  Originally  published  in  Circulares  del  Museo  y 
Biblm.  Zool.  Habana,  1972.  pp.  1.526-1649. 

Davis,  George  M.  1979.  The  Origin  and  Evolution  of  the 
Gastropod  Family  Pomatiopsidae,  with  Emphasis  on  the 
Mekong  River  Triculinae.  Monograph  20.  Acad.  Nat.  Sci. 
Philiulclphia.  120  pp.  An  extensive  zoogeographic  and 
phylogenetic  review,  with  two  new  genera.  The  author 
employs  the  of  Triljes  and  erects  two  new  names  under 
the  subfamily  Triculinae. 

Gate,  Crawford  N.  1979.  A  Review  of  the  Tiiviidae.  Memoir 
10,  San  Diego  Society  of  Naiural  Histoi-y.  126  pp.,  177  figs. 
An  extensive  review,  with  five  new  genera  and  40  new 

Zhuang.  Qi-qian.  1978.  Studies  on  the  Mesodesmatidae 
(Lamellibranchia)  off  the  Chinese  Coast.  Studia  Marina 
Sinira.  vol.  14.  no.  14,  pp.  69-74,  1  pi.  Treats  with  Atactodea, 
Darila  Oiccclla  and  Anapelta  retrocunvexa  n.  sp.  from 
N;ur/,how  Island,  China. 

Pidmonates.  Vol.  2  A,  Systematics.  Evolution  and  Ecology 
(edited  by  V.  Fretter  and  J.  Peake).  .540  pp.  Academic  Press, 
London,  N.  Y.  1979.  $50.75.  10  chapters  of  varying  contents 
and  quality,  some  outstanding  on  systematics.  distribution, 
classification,  natural  selection  and  ecology  by  fourteen 
well-known  malacologists. 

Pulmonates.  Vol.  2  B,  Economic  Malacolugy  u-ith  particular 
reference  to  Achaiina  fulica.  by  A.  R.  Mead.  1.50  pp. 
Academic  Press,  London,  N.  Y.  1979.  $2,520.  This  is  an  up- 
date and  condensed  version  of  Dr.  Mead's  1961  "The  Giant 
African  Snail"  ($8.00).  A  previous  book.  Medical  and 
Economic  Malacology,  by  Malek  and  Cheng,  published  by 
Academic  Press  in  1974,  covers  the  economic  field  more 
broadly  and  adequately. 


by  Philippe  Bouchet 
Photography  by  F.  Danrigal  and  C.  Huyghens 

An  exquisite  little  guide  to  the  habits, 
life  histoiT  and  identification  of  the  com- 
mon moUuskes  of  Western  Europe.  142 
spectacular,  colored  photographs  of  egg- 
laying,  breeding,  and  reproducing,  as  well 
as  very  colorful,  close-up  views  of  snails, 
nudibranchs,  clams  and  squids.  Also  con- 
tains 11  plates  of  identification  figures.  One 
of  the  loveliest  of  the  new  generation  of 
shell  books.  Hardback.  144  pp.  $8.95. 
Published  by 

American  Malacologists,  Inc. 

P.O.  Box  2255 
Melbourne,  FL  .32901  USA 

Vol.94  (1) 

October  30, 1979 





Donald  M.  Allen 

NOAA,  National  Marine  Fisheries  Service 

S(iutheast  Fisheries  Center 

Miami,  Florida  33149 


Biological  information  on  the  calico  scallop.  Argopecten  gibbus,  was  collected 
using  spat  traps  as  monitoring  devices  on  the  Cape  Canaveral  grounds  off  the 
Florida  east  coast  from  March  1970  to  October  1971.  The  shells  of  noung  scallops 
(spat)  differ  in  shape  and  color  from  those  of  adult  scallops.  Spat  and,  by  deduc- 
tion, the  larval  scallop.%  occurred  at  five  sampling  locations  off  Cape  Canaveral  in 
depths  of  9  to  2Jf  m;  spat  were  most  abundant  at  the  18  m  site.  There  was  no 
evidence  that  scallop  larvae  survived  in  estuarine  waters  in  the  Cape  Canaveral 
area.  Based  on  spat  distribution,  la}-vae  were  apparently  distributed  throughout 
the  water  column  but  were  least  abundant  near  the  surface.  Seasonally,  spat  were 
most  abundant  in  the  spring.  Growth  estimates  .show  that  young  scallops  can  reach 
1.5  m,m  shell  height  in  1  month  from  spawning,  17.0  mm  in  2  months,  and  28.0  mm 
in  3  months.  Setting  apparently  occun-ed  at  a  minimum  size  of  0.25  mm  shell 
height  and  apnt  showed  strong  byssal  attachment  up  to  at  least  5.0  or  6.0  mm  shell 
height.  Spat  may  utilize  filamentous  host  organisms,  such  as  hydroids.  for  setting, 
perhaps  before  attaehment  to  shell.  Numerous  inveHebrates  were  associated  with 
calico  .scallops  in  the  traps,  but  calico  scallops  ivere  generally  dominant. 

Based  on  spat  abundance,  spawning  of  adults  occurred  during  all  seasons,  but 
intensity  was  highest  in  spring  (March  through  May)  when  bottom  water 
temperatures  associated  unth  spauming  scallops  were  probably  about  18°C. 

Recommendations  for  future  spat  monitoring  are  discussed. 

The  calico  scallop,  Argopecten  gibbus,  supports 
a  small  fishery  off  the  southeastern  United 
States.  The  scallop  grounds  are  located  off  North 
Carolina,  off  the  Florida  east  coast,  and  in  the 
northeastern  Gulf  of  Mexico  (Figure  1).  Abun- 
dance and  distribution  of  scallops  on  the  grounds 
are  seasonally  and  annually  variable,  which  has, 
in  part,  contributed  to  the  slow  development  of 
the  fishery.  To  recognize  factors  controlling  the 
abundance  and  distribution  of  the  calico  scallop, 
the  Bureau  of  Commercial  Fisheries  (now  the  Na- 
tional Marine  Fisheries  Service),  Miami,  Florida, 
conducted  laboratory  and  field  studies  of  the 
biology  of  this  species  from  1969  to  1971. 

Biological  information  concerning  certain 

'  Contribution  Number  79-37M,  NOAA,  National  Marine 
Fisheries  Service,  Southeast  Fisheries  Center.  Miami,  FL 

marine  invertebrates  has  been  revealed  by  their 
habit  of  attaching  to  or  "fouling"  of  submerged 
objects  (Woods  Hole  Oceanographic  Institution, 
1952;  Merrill,  1965).  Artificial  substrates,  such  as 
test  surfaces  or  fouling  panels,  are  used  in 
biological  monitoring  because  of  the  relative  ease 
with  which  the  unit  of  sampling  effort  can  be 
standardized  and  controlled  (Calder  and 
Brehmer,  1967;  Cory,  1967;  Pequegnat  and  Pe- 
quegnat,  1968).  Spat  collecting  devices,  made  of 
oyster  shells  or  asbestos  plates,  are  particularly 
useful  in  oyster  biological  studies  that  have 
direct  application  to  the  commercial  fishery 
(Loosanoff,  1966;  Shaw,  1967). 

Scallops  (family  Pectinidae)  attach  to 
substrates  by  means  of  byssal  threads.  The  first 
byssal  attachment  of  young  scallops  after  a 
planktonic  existence  is  called  "setting,"  and  the 


October  30, 1979 

Vol.  94  (4) 

FIG.  1.  G(  ncnil  dixlribtituin  af  the  calicu  scattop  and  primary 
scallop  fishing  grtmnds.  (Modified  fi^om  Cummins,  1971:  A  Hen 
and  Oistello.  1972). 

recently  set  scallops  are  called  "spat."  Setting 
was  described  for  the  bay  scallop,  Pecten  irra- 
diaiK  (now  Atyopecteti  irmdians),  by  Belding 
(1910).  Young  scallops  of  various  species  will  set 
on  natural  and  artificial  substrates  (Belding, 
1910;  Woods  Hole  Oceanographic  Institution, 
1952;  Merrill,  1965;  Brown  et  al.,  1967;  Dow, 
1969;  Costlow,  1969;  DePalma,  1969;  Turner, 
Egbert,  and  Given,  1969  and  Golikov  and  Scarlato, 
1970.)  Under  natural  conditions,  calico  scallop 
spat  are  generally  found  attached  to  mollusk 
shells,  primarily  the  empty  valves  of  calico 
scallops  (Allen  and  Costello,  1972).  Calico  scallop 
spat  have  also  attached  to  navigation  buoys 
(Waller,  1969)  and  plastic  peanut  floats  (Pe- 
quegnat,  Gaille,  and  Pequegnat,  1967). 

The  setting  habits  of  scallops  suggested  that 
calico  scallop  spat  might  be  effectively  sampled 
using  artificial  substrates  as  collecting  devices. 
An  effective  spat  collector,  briefly  described  by 
Allen  and  Costello  (1972),  was  developed  by  me  in 
early  1970.  Later  spat  monitoring,  using  this 
device,  provided  basic  data  concerning  spat: 
description,  distribution  and  abundance,  age  and 
growth,  behavior,  and  associated  organisms;  and 
spawning  of  adults.  In  recent  years,  a  similar 
spat  collecting  device  has  been  used  in  a  Japanese 
commercial  scallop  culture  system  (Dix,  1977). 

In  preliminary  field  tests  off  Cape  Canaveral, 
Florida  (Figure  2),  young  calico  scallops  byssally 
attached  to  a  variety  to  cultch  materials  in  addi- 

tion to  calico  scallop  shells.  Unlaid  polyethylene 
line,  which  forms  a  filamentous  tangle,  was  par- 
ticularly effective  as  cultch.  Comparison  of  cultch 
effectiveness  was  difficult  because  many  of  the 
larger  spat  dropped  from  the  cultch  as  it  was 
removed  from  the  ocean.  To  minimize  the  loss  of 
spat  that  may  release  attachment  before  or  dur- 
ing the  time  spat  collectors  were  retrieved,  the 
cultch  was  contained  within  wire  plastic  or 
nylon  mesh  of  appropriate  size. 

The  standardized  spat  collector  (designated 
"spat  trap")  used  during  most  of  this  study  con- 
sisted of  a  small,  nylon  mesh  bag  stuffed  with  a 
fixed  quantity  of  unlaid  polyethylene  line  (Figure 
3).  The  nylon  bag  was  56.0  cm  long  and  30.5  cm 
wide,  with  mesh  openings  about  3.0  mm  in 
diameter.  Polyethylene  line,  diameter  9.4  mm  and 
length  61.2  cm,  was  separated  into  individual 
filaments  and  placed  in  the  bag,  along  with  a 
plastic  identification  label.  The  bag  was  closed  by 
means  of  a  figure-eight  knot  tied  in  the  bag  at  its 
midpoint.  Excess  bag  material  was  drawTi  down 
over  the  knot  and  tied  with  nylon  parachute 
cord,  which  also  secured  the  spat  trap  to  a  ver- 
tical line  at  a  selected  position  in  the  water  col- 
umn. These  spat  traps  survived  well  in  the 
marine  environment,  because  their  components 
did  not  decompose  rapidly. 

The  spat  traps  filtered  large  quantities  of 
water  from  currents  which  presumably  carried 
the  scallop  larvae  to  the  traps  where  the  larvae 
set  and  grew.  Young  scallops  inside  the  traps 
were  permanently  trapped  when  their  size  ex- 
ceeded the  3.0  mm  mesh  openings.  Probably  few 
spat  less  than  3.0  mm  shell  height^  were  lost 
during  recovery  of  the  traps  because  spat  in  this 
size  category  show  strong  byssal  attachment. 

Preliminary  comparative  studies  indicate  that 
standard  spat  traps  containing  61.2  cm  of  unlaid 
line  caught  more  spat  than  mesh  bags  containing 
no  line  but  stretched  with  wire  to  a  size  and 
shape  similar  to  that  of  the  standard  traps.  When 
the  amount  of  line  in  the  traps  was  increased  to 
183.6  cm,  the  numbers  of  spat  caught  increased, 
but  their  growth  declined  markedly.  Further- 
more, the  tightly  packed  line  apparently  caused  a 
high  incidence  of  deformed  valves  and  mortality 
among  the  larger  spat.  As  noted  by  Merrill  and 

'  Shell  heipht  is  a  straight  measurement  of  the  greatest 
distance  between  the  umbo  and  the  ventral  margin. 

Vol.  91  (4) 

October  30, 1979 


■■■  \ 


yV       luo't  I     •"<>'  2 

vXv      '^ 


\     1    1    Jy^*''^    CANAVERAL 

i     1    )  \.^t,             ifOilCiMVtlU 


-  <y.'' 



— r- 




FIG.  2.  Calif  (J  ^calhip  tspat  mimitnring  siten  nff  Cape 
Caiuiveral  and  geographic  locations  along  the  eiixt  count  of 

Edwards  (1975)  for  young  sea  scallops, 
Placopecten  magellanicus.  growing  in  fouling 
communities,  "The  mantle  is  apparently  easily 
injured,  and  evidence  of  serious  shell  malforma- 
tion was  seen  in  situations  where  other 
organisms  were  in  close  approximation  to  the 
scallop."  In  the  standard  spat  traps,  no  defor- 
mities occurred.  Extensive  mortality  did  occur  in 
standard  traps  that  were  exposed  for  almost  4 
months,  but  the  causes  are  unknovm.  These  traps 
contained  potential  predators  (including  starfish, 
crabs,  and  gastropod  mollusks)  and  competitors 
(bivalve  mollusks)  that  had  apparently  passed 
through  the  meshes  as  larvae  and  were 
themselves  trapped.  In  addition,  the  meshes  were 
clogged  with  silt. 

Five  sites  to  monitor  calico  scallop  spat 
distribution  and  abundance  were  established  off 
the  Florida  east  coast  near  Cape  Canaveral,  in 
depths  of  9  to  24  m  (Table  1,  Figure  2).  U.S.  Coast 
Guard  navigation  buoys  or  special  service  buoys 
marked  each  site  and  enabled  location  and 
recovery  of  the  spat  traps  after  exposure  for  ex- 
tended periods  of  time.  It  was  necessary  to 
establish  the  sites  inshore  of  the  greatest  adult 
scallop  concentrations  because  of  the  absence  of 
large,  permanent  buoys  in  the  offshore  waters. 

Adult  scallops  occurred  near  Buoys  1  and  2  but 
were  rare  or  absent  at  the  remaining  three  sites. 

In  use,  the  spat  traps  were  attached  to  a  spat 
monitoring  array  that  was  typically  composed  of 
an  anchor,  vertical  line,  stabilizing  float  and  sur- 
face buoy.  To  facilitate  recovery,  the  arrays  were 
positioned  within  sight  of  the  permanent  buoy  at 
each  site.  In  some  areas,  where  danger  of  propeller 
cutoff  and  theft  was  great,  the  surface  buoy  was 
retained  underwater  until  released  by  a  timed 
magnesium  fuse  shortly  before  scheduled  recovery. 
For  most  of  the  comparative  studies,  two  spat  traps 
were  located  on  the  vertical  line  at  positions  0.6  m 
and  6.0  m  above  the  ocean  bottom.  For  special  pur- 
poses, additional  traps  were  located  0.9  m  below  the 
water  surface  and  elsewhere  in  the  water  column. 

The  preliminary,  experimental  spat  collecting 
devices  were  first  set  out  in  March  1970.  After 
refining  techniques,  standardized  spat  traps, 
useful  for  comparing  abundance,  were  exposed  for 
varying  periods  of  time  from  July  1970  to  Oc- 
tober 1971.  Scallops  caught  by  both  the 
preliminary  and  standardized  traps  were  used  in 
the  growth  study.  The  shortest  exposure  time  was 
11  days,  and  the  longest,  117  days.  Losses  of  ar- 
rays were  common  and  were  attributed  to  strong 
currents,  entanglement  with  fishing  gear,  theft, 
and  propeller  cut-off.  Most  of  the  successful 
recoveries  of  arrays  were  at  Buoys  1  and  2,  the 
sites  most  remote  from  vessel  traffic  or  fishing 

When  the  spat  traps  were  recovered  from  the 
ocean,  they  were  placed  in  fine-mesh  nylon  bags 
(mesh  size  about  0.75  mm)  and  preserved  in  10% 
Formalin.'  Although  the  spat  apparently  released 
byssal  attachment  upon  contact  with  Formalin, 
the  fine-mesh  preserving  bags  retained  spat  as 
small  as  0.75  mm  shell  height  and  helped  main- 
tain the  integrity  of  each  spat  trap  during  the 
later  flushing,  freezing  (for  preservation),  and 
thawing  process. 

The  calico  scallop  spat  (including  empty  shells) 
and  associated  organisms  from  each  spat  trap 
were  sorted  and  counted.  An  unknowm  number  of 
very  small  spat  (less  than  0.75  mm  shell  height) 
may  have  been  washed  through  the  fine-mesh 
preserving  bag  or  overlooked  by  the  sorters. 
Other  species  of  scallops  were  caught  in  the  traps 

'  Reference  to  trade  names  does  not  imply  endorsement  by 
the  National  Marine  Fisheries  Service,  NOAA. 


October  30. 1979 

Vol.  94  (4) 

but  constituted  less  than  1%  of  those  larpe 
enough  to  be  identified  to  species.  The  scallop 
spat  were  measured  for  shell  height.  Spat  less 
than  1.0  mm  shell  height  were  measured  to  the 
nearest  0.25  mm,  those  from  1.0  to  5.0  mm  to  the 
nearest  0.5  mm,  and  those  more  than  5.0  mm  to 
the  nearest  1.0  mm.  Scallops  from  0.25  to  27.0 
mm  shell  height  were  found  in  the  trap  samples. 
One  trap,  exposed  for  35  days,  contained  4,761 
spat  that  ranged  from  0.75  to  8.0  mm  shell  height. 

Since  the  "catching  effort"  of  the  spat  traps 
varied  with  exposure  time,  catch  data  were  stan- 
dardized by  calculating  the  average  number  of 
spat  caught  per  trap  per  day  of  exposure. 

Thermographs  recorded  bottom  temperatures 
at  Buoys  1  and  2  during  most  of  the  study  period, 
but  there  were  intervals  when  no  data  were  col- 
lected because  of  thermograph  malfunction  or 



The  calico  scallop  shell  was  described  by 
Waller  (1969).  Shells  of  calico  scallop  spat  col- 
lected in  spat  traps  on  the  Cape  Canaveral 
grounds  (Figure  4)  differed  in  shape  and  color 
from  shells  of  adult  scallops  collected  in  the  same 

Shell  height  was  usually  greater  than  shell 
length"  in  .spat  1.0  to  8.0  mm  height.  At  about 
9.0  mm  shell  height,  shell  length  began  to  in- 
crease more  rapidly  than  shell  height,  and  from 
my  additional  observations  of  larger  scallops,  and 
those  of  Wells,  Wells,  and  Gray  (1964),  this  rela- 
tionship apparently  continued  throughout  life.  In 

Table    1.      Locations   aod   depths   of   calico   scallop    spat  monitoring    sites 
off  Cape  Canaveral,    Florida. 






trom   land 




Buoy    1 







38.  b 


Buoy    2 


49.  l] 







Heczel   Shoal 










Port  C«Dsveral 






R2  Buoy 




Port  Caooveral 






RUlt6  Buoy 




FIG.  3.  Spat  trap,  cmutisting  nf  nylon  mesh  bag  (top)  and 
unlaid  palyethylene  line  (bottom  right).  Calico  acallap  spat 
(center)  exceed  mesh  openings  in  size.  (Prom  Allen  and 
Costello.  19721. 

trawl-caught  scallops,  shell  length  did  not  begin 
to  increase  more  rapidly  than  shell  height  until  a 
shell  height  of  about  30.0  mm  was  reached. 

Length  of  the  hinge  line  was  about  equal  to 
shell  length  in  spat  1.0  to  1.5  mm  shell  height. 
However,  as  shell  height  increased,  hinge  line 
length  increased  more  slowly,  so  that  at  8.0  mm 
shell  height  (approximately  8.0  mm  shell  length) 
hinge  line  length  was  6.0  mm. 

Spat  less  than  about  10.0  mm  shell  height  were 
noticeably  compressed,  or  flattened,  as  compared 
with  the  strongly  inflated  adult  scallops.  For  spat 
ranging  from  3.5  to  8.0  mm  shell  height,  depth'^ 
was  only  about  27  to  31%  of  shell  height.  As  shell 
height  increased,  depth  increased  disproportion- 
ately. For  spat  19.0  to  23.0  mm  .shell  height, 
depth  was  about  37  to  46%  of  shell  height,  and 
for  scallops  37.0  to  65.0  mm  shell  height  (caught 
by  bottom  trawl),  depth  was  about  54  to  64%  of 
shell  height. 

There  was  a  difference  in  convexity*  between 
the  left  (upper)  and  right  (lower)  valves  in  spat 
from  1.5  mm  up  to  at  least  8.0  mm  shell  height. 
For  spat  3.5  to  4.5  mm  shell  height,  the  left  valve. 

'  Shell  length  i.s  a  straight  line  mea.-iurement  of  the  greatest 
distance  between  the  anterior  and  posterior  margins. 

'  Depth  is  the  sum  of  the  convexities  (see  footnote  (i)  of  the 

left  and  right  valves. 

'  Conve.xity  is  the  maximum  distance  lietween  the  exterior 
surface  of  a  v.dve  and  the  measuring  platfunn.  me;usured 
along  a  line  perpendicular  to  the  measuring  platform  (Waller, 

V(,1.91  (1) 

October  30, 1979 


FIG.  4.  Calico  scallop  spat  from  2.5  to  16.0  mm  shell 
valve  in  on  bottom. 

strongly  convex,  accounted  for  65  to  81%  of  the 
depth,  while  the  right  valve,  weakly  convex,  ac- 
counted for  only  18  to  34%  of  the  depth.  Convexi- 
ty of  the  valves  became  more  equal  as  shell 
height  increased.  Waller  (1969),  apparently 
discussing  adult  scallops,  observed  that  the  valves 
were  "generally  equiconvex  to  slightly  left  con- 

Spat  ranging  from  0.75  to  18.0  mm  shell  height 
had  white,  tan,  violet,  brovm,  red-brown,  and 
orange-brown  valves.  Some  mottling  or  banding 
occurred  on  spat  as  small  as  2.0  mm  shell  height. 
Colors  on  the  left  valve  were  darker  than  those 
on  the  right  valve,  which  was  generally  white  or 
light  tan.  Colors  on  the  left  valve  became  darker 
and  more  intense  as  size  increased.  White  and 
tan  were  common  base  colors  on  the  left  valve  of 
spat  0.75  to  8.0  mm  shell  height,  grading  into 
brown  and  red-brown  as  size  increased  up  to  18.0 
mm  shell  height. 

A  fairly  common  characteristic  of  spat,  par- 
ticularly those  from  about  4.0  to  8.0  mm  shell 
height,  was   a   white  streak   bisecting   the   left 

height.  For  e<wh  pair,  kjt  rale 

lilt  top  and  right 

valve,  extending  from  near  the  umbo  to  the  ven- 
tral margin  and  encompassing  the  width  of  a  few 

LHstribution  and  Abundance 

The  general  distribution  of  the  calico  scallop 
was  summarized  from  several  sources  by  Allen 
and  Costello  (1972),  who  stated  that  the  range  of 
this  species  ".  .  .  extends  from  the  northern  side 
of  the  Greater  Antilles  and  throughout  the  Gulf 
of  Mexico  to  Bennuda  and  slightly  north  of  Cape 
Hatteras."  According  to  Allen  and  Costello  (1972), 
"The  greatest  known  abundance  is  located  off  the 
Florida  east  coast  near  Cape  Kennedy  [Cape 
Canaveral],  with  lesser  concentrations  near  Cape 
Lookout,  N.  C,  and  in  the  northeastern  Gulf  of 
Mexico  near  Cape  San  Bias,  Fla."  Sporadic  com- 
mercial concentrations  also  have  been  reported 
off  Savannah,  Georgia,  and  along  the  west  coast 
of  Florida,  from  off  Egmont  Key  to  Key  West 
(Figure  1). 

Although  the  calico  scallop  may  consist  of  one 
population  throughout  its  range,  with  planktonic 
larvae  from  stock  in  one  area  contributing  to 


October  30, 1979 

Vol.  94  (4) 

stock  in  another  area,  there  is  little  evidence  to 
suprK)rt  this  theory.  Oceanic  currents  probably 
determine  the  direction  of  transport  of  the  lan'ae 
(Waller,  1969).  Therefore,  the  Gulf  Stream 
system,  and  associated  countercurrents,  may  be 
important  in  larval  distribution.  Kirby-Smith 
(1970)  suggested  that  part  of  the  North  Carolina 
calico  scallop  stock  may  result  from  larvae 
transported  northward  from  the  Cape  Canaveral 
grounds  by  the  Gulf  Stream.  The  origin  of  the 
calico  scallops  on  the  Cape  Canaveral  grounds  is 
unknown.  These  scallops  may  be  either  self- 
sustaining  or  partially  dependent  upon  larvae 
transported  from  more  distant  spawning  stocks, 
presumably  (but  not  necessarily)  located  farther 
south  than  the  lower  end  of  the  Cape  Canaveral 
grounds  near  Stuart,  Florida.  Calico  scallops  oc- 
cur in  the  Florida  Keys  (Waller,  1969),  and  these 
scallops  may  supply  larvae  to  the  Cape  Canaveral 
grounds  (Figure  2).  This  hypothesis,  however, 
does  not  negate  the  fact  that  there  is  a  large 
stock  of  spawning  scallops  on  the  Cape  Canaveral 
grounds,  and  water  circulation  in  the  Cape 
Canaveral    area    might    be    expected    to    retain 

scallop  larvae  on  the  grounds  until  setting  occurs, 
since  surface  currents  off  Cape  Canaveral  reverse 
direction  to  north  or  south  with  wind  changes, 
and  bottom  currents  converge  toward  the  cape 
from  offshore  (Bumpus,  1973). 

Calico  scallop  spat  were  caught  in  traps  at  all 
five  study  sites  off  Cape  Canaveral  (Table  2).  This 
might  be  e.xpected  since  the  wide  distribution  of 
adult  scallops  on  the  Cape  Canaveral  grounds 
(Drummond,  1969)  would  presumably  contribute 
to  the  wade  distribution  of  larvae  in  this  area. 
The  intensity  of  spat  setting  (or  survival)  be- 
tween sites  was  variable.  Where  mmparisons  be- 
tween sites  could  be  made,  they  showed  spat  to 
be  most  abundant,  generally,  at  Buoy  1  and  least 
abundant  at  Port  Canaveral  RWR6  Buoy.  For  ex- 
ample, traps  exposed  from  May  25  to  June  26, 
1971  (35  days)  caught  2,320  spat  at  Buoy  1  (9  km 
offshore,  18  m  of  water),  895  spat  at  Buoy  2  (22 
km  offshore,  22  m),  and  21  spat  at  Port  Canaveral 
RWR6  Buoy  (6  km  offehore,  9  m)  (Table  2). 
Variability  in  setting  between  locations  was  also 
observed  in  the  northeastern  Gulf  of  Mexico, 
where  calico  scallop  spat  attached  to  biofouling 

Table  2.   Seasonal  abundance  of  calico  scallop  spat  at  monitoring  sites  oft  Cape  Canaveral,  Florida,  July  1970  to  October  1971. 

Spat  Trap   hxposure 

Buoy    1 

Buoy    1 



Shoal    Buoy 
Per   day 

Port  Canaveral 
R2   Buoy 

Port   Canaveral 
RWR6  Buoy 

Period                       Daya 

Total           Per   day 

Total    Per   day 

Total           Per   day 

Total           Per   day 




227  6.5 

39  0.5 

134  1.8  139  1.9 

4,562  130.3  1,531  43.7 

2,300  65.7  1,181  33.7 

2,320  72.5  895  28.9 

142  2.4  536  9.1 

21  0.3  70  1.1 

-number    of    spat      per    trap    










0.  1 

1  Spat   size   ranged   from  0.23  to  27.0  mm  shell  height. 

2  Spat   traps  were  positioned   about   0.6  m  above  ocean   floor. 

3  Dashes   Indicate   no  data   (i.e.,   trap  was  not  exposed,  or   if  exposed,   not    recovered). 

Vol.94  (4) 

October  30, 1979 


Table   3.      Vertical    distribution  of   calico   scallop   spat   at  monitoring    sites   off    Cape   Canaveral, 
Florida,    November    19/U   to   October   1971. 

Buoy    1 

Buoy    2 

Spat    trap   e 









11/11/7U   - 





er   of    spat 

per    trap 

per   day 



1/24/71    - 








3/16/71    - 








4/20/71    - 








5/25/71    - 








6/26/71    - 








8/24/71    - 







1.  1 

1     Dashes   indicate   no   data. 

Note:      Surface    traps   were   positioned    about    0.9   m 
above   ocean   floor,   and   bottom   traps    0.6   m 

arrays  more  abundantly  at  sites  19  km  offshore 
than  at  sites  4  or  41  km  offehore  (Pequegnat  and 
Pequegnat,  1968). 

The  usual  distribution  of  adult  calico  scallops 
indicates  that  the  larvae  are  restricted  to  open 
marine  water.  The  larvae,  however,  sometimes 
enter  estuarine  waters,  based  on  reported  oc- 
currences in  semi-enclosed  sounds  of  juveniles  in 
North  Carolina  (Waller,  1969)  and  adults  in  Ber- 
muda (Aurelia,  1970).  There  was  no  evidence  that 
the  larvae  survived  and  set  in  estuarine  waters  in 
the  Cape  Canaveral  area.  Relatively  few  spat 
were  caught  at  Port  Canaveral  RWR6  Buoy,  the 
site  closest  to  shore  and  to  an  estuarine  inlet 
(Figure  2,  Table  1).  Furthermore,  a  year-long 
biofouling  study  at  nearby  Ponce  de  Leon  Inlet 
produced  three  species  of  mollusks,  but  no 
scallops  (Richards  and  Clapp,  1944). 

Larval  calico  scallops  are  apparently 
distributed  throughout  the  water  column,  since 
spat  were  found  in  traps  positioned  at  the  ocean 
surface,  at  intermediate  depths,  and  near  the  bot- 
tom (Table  3).  Similar  vertical  distribution  of  lar- 
vae was  indicated  by  Pequegnat  and  Pequegnat 
(1968)  who  reported  calico  scallop  spat  from 
biofouling  arrays  distributed  from  surface  to  bcjt- 
tom  in  46  m  of  water  in  the  northeastern  Gulf  of 

below  ocean   surface,    intermediate    traps    6.0   m 
above   ocean    floor. 

Mexico.  Off  Cape  Canaveral  at  Buoys  1  and  2, 
from  April  20  to  May  25,  1971,  there  were  very 
few  spat  in  the  surface  traps  as  compared  with 
those  in  the  intermediate  and  bottom  traps.  At 
each  of  these  two  sites,  comparisons  of  in- 
termediate and  bottom  catch  rates  between 
November  1970  and  October  1971,  showed  that 
vertical  distribution  of  spat  was  highly  variable 
during  certain  exposure  periods,  indicating  varia- 
tions in  larval  abundance  or  spat  survival  be- 
tween the  intermediate  depths  and  the  bottom  at 
these  seasons  (Table  3). 

Calico  scallop  spat  were  caught  year-round  in 
traps  off  Cape  Canaveral;  at  least  a  few  spat 
were  caught  during  every  exposure  period  (Table 
2).  This  suggests  continuous  recruitment  of  young 
scallops  to  the  population  on  the  grounds, 
although  there  may  not  be  a  simple  relationship 
between  setting  success  in  the  traps  and  success 
on  natural  substrate  in  the  immediate  area.  For 
example,  while  the  numbers  of  spat  at  Buoy  1 
generally  exceeded  those  at  Buoy  2  (Table  2), 
trawl  catches  of  adult  scallops  on  the  ocean  floor 
at  Buoy  2  greatly  exceeded  those  at  Buoy  1.  The 
substrate  at  Buoy  1  consisted  of  sand  and  flat 
conglomerate  rocks,  while  that  at  Buoy  2  was 
sand  and  live  shell  rubble. 

Ill  thp:  nautilus 

October  3U.  1979 

Vol.94  (4) 

There  were  distinct  seasonal  variations  in  spat 
abundance.  At  Buoy  1,  between  July  21,  1970  and 
October  27,  1971,  catches  ranged  from  0.3  to  130.0 
spat  per  trap  per  day.  Based  on  catches  at  Buo.v 
1,  where  the  data  are  most  complete,  and  sup- 
plemented by  data  from  Port  Canaveral  R2  Buoy, 
the  great  majority  of  spat  were  caught  in  traps 
exposed  between  January  6  and  June  26,  1971, 
with  peak  numbers  from  March  16  to  April  20, 
1971.  Relatively  few  spat  were  caught  during  the 
remainder  of  the  year.  A  similar  pattern  of  spat 
abundance  occurred  at  Bu(jy  2(Table  2). 

Age  and  Growth 

Age  and  growth  of  young  calico  scallops  were 
estimated  from  the  maximum  sizes  of  spat  caught 
in  the  spat  traps  at  the  end  of  each  exposure 
period.  For  example,  spat  traps  exposed  for  35 
days  contained  spat  ranging  from  0.25  to  10.0  mm 
shell  height;  the  size  composition  from  one  trap 
is  shown  in  Figure  5.  Assuming  no  movement  of 
spat  into  the  traps  after  initial  setting,  the  set- 
ting time  of  these  scallops  had  to  be  within  the 
35-day  exposure  period.  Under  laboratory  condi- 
tions, calico  scallop  larvae  set  16  days  after 
spawning,  at  about  0.25  mm  shell  height  (Costello 
et  al.,  1973).  Therefore,  age  of  the  10.0  mm  spat  in 
the  traps  could  not  exceed  51  days  (16  days  from 
spawning  to  set,  plus  a  maximum  of  35  days  in 
the  traps.)  In  estimating  growth,  it  was  assumed 
that  the  largest  spat  in  the  traps  (10.0  mm  .shell 
height)  set  on  the  first  day  of  trap  e.xposure. 
Evidence  that  spat  set  soon  after  the  traps  were 
exposed  was  based  on  the  size  ranges  of  spat  in 

1         234567B9I0 

FIG,  .5.  Size  composition  of  calico  scallop  spat  from  spat  trap 
exposed  at  Biuiij  1  off  Cape  Canaveral  Florida,  April  20  to 
Mail  £>.  1971. 

ACE    rN  DAYS 

FIG.  ().  KsliiHuted  aye  and  yrimih  of  eidico  scallop  spat  from 
spat  traps  exposed  off  Cape  Canaveral.  Florida  March  1970  to 
Cktober  1971.  Age  U  number  of  days  from  spawning  to  set 
I  Hi)  plus  number  of  days  of  spitt  trap  exposure. 

traps  exposed  for  short  periods  of  time.  In  one 
trap  exposed  for  11  days,  many  spat  from  0.25  to 
1.0  mm  shell  height  were  found.  Since  spat  set  at 
0.25  mm  shell  height,  it  is  reasonable  to  expect 
that  the  1.0  mm  .spat  set  first,  on  or  soon  after 
the  first  day  of  trap  exposure.  While  this 
assumption  regarding  time  of  spat  setting  may 
not  be  entirely  correct  for  all  situations,  it  is 
probably  the  best  assumption  that  can  be  made 
based  on  the  available  data.  If  it  is  assumed  that 
the  largest  spat  set  after  the  first  day  of  trap  ex- 
posure, then  estimated  growth  would  be  more 
rapid  than  reported  here. 

Tliis  method  of  estimating  age  as  related  to 
size  was  applied  to  the  largest  spat  from  each  ex- 
posure period  and  the  results  are  shown  in 
Figure  6.  Based  on  these  data,  calico  scallops  are 
capable  of  reaching  approximate  sizes  of  1.5  mm 
shell  height  in  1  month  from  spawTiing,  17.0  mm 
in  2  months,  and  28.0  mm  in  3  months.  This 
growth  rate  is  compatible  with  results  of 
preliminary  studies  of  marked  calico  scallops  on 
the  Cape  Canaveral  grounds,  reported  by  Miller 
and  Hudson',  which  indicate  that  scallops  reach 
40  to  45  mm  shell  height  in  6  to  8  months. 

'  Miller,  G.  C.  and  J.  H.  Hudson.  Age  and  growth  of  the  calico 
scallop,  Argopecten  gibbits.  Manuscript  in  preparation.  Na- 
tional Marine  Fisheries  Service.  Southeast  Fisheries  Center. 
Miami  Laboratory.  Miami.  FL  :fil49. 

Vol.  94  (4) 

October  30, 1979 


Preliininaiy  studies  indicate  that  growth  rate 
of  spat  in  the  traps  is  affected  by  location  in  the 
water  column  and,  probably,  by  the  density  of 
spat.  At  Buoy  2,  spat  in  a  trap  0.6  m  above  the 
ocean  bottom  grew  more  rapidly  than  those  in 
traps  6.0  m  off  the  bottom  and  0.9  m  below  the 
water  surface.  Similarly,  Merrill  and  Posgay 
(1968)  observed  that  juvenile  sea  scallops  grew 
faster  on  the  ocean  bottom  than  on  navigation 
buoys.  Also  at  Buoy  2,  in  three  traps  located  0.6 
m  off  the  bottom  and  exposed  for  72  days,  the 
maximum  size  of  spat  in  each  trap  decreased 
with  increased  number  of  spat  per  trap. 


Information  concerning  setting  and  byssal  at- 
tachment of  calico  scallops  in  respect  to  size  has 
been  reported  briefly.  The  larvae  set  at  about  0.25 
mm  shell  height  in  the  laboratory  (Gistello  ct  al., 
1973).  Calico  scallop  spat  have  been  reported  by 
size  and  attachment  as  follows:  1  to  8  mm 
(presumably  shell  height)  from  plastic  floats  (Pe- 
quegnat,  Gaille,  and  Pequegnat,  1967);  2.0  to  7.5 
mm  shell  length,  among  epifauna  on  shells  of  liv- 
ing calico  scallops  (Wells,  Wells,  and  Gray,  1964); 
and  3  to  5  mm  shell  length,  attached  to  the  shells 
of  dead  calico  scallops,  primarily  (Commercial 
Fisheries  Review,  1962). 

The  sea  scallop  showed  a  progressive  loss  of 
byssal  attachment  as  size  increased  (Caddy,  1972). 
The  calico  scallop  apparently  behaves  similarly, 
from  observations  on  recovered  spat  traps.  Off 
Cape  Canaveral,  setting  apparently  occurred  at  a 
minimum  size  of  0.25  mm  shell  height,  since  this 
was  the  minimum  size  of  spat  in  the  trap 
samples.  Strong  byssal  attachment  to  the  ex- 
teriors of  the  traps  was  shown  by  spat  up  to  at 
least  5.0  or  6.0  mm  shell  height.  Very  few  spat 
larger  than  10.0  mm  in  height  were  found  at- 
tached to  the  exteriors  of  the  traps  at  recovery, 
although  many  spat  larger  than  10.0  mm  were 
contained  inside  the  traps  where  escape  was  im- 
possible. This  size  difference  suggests  weakened 
byssal  attachment  by  the  larger  spat,  since  most 
had  apparently  detached  from  the  e.xteriors  of  the 
traps  upon  reaching  10.0  mm  shell  height  or  were 
dislodged  during  trap  recovery.  Calico  scallops  as 
large  as  38  mm  shell  height  occasionally  wei-e 
found  attached  to  dead  scallop  shells  in  trawl 
catches  on   the  Cape  Canaveral  grounds.   From 

observations  on  calico  scallops  resting  on  the  bot- 
tom, in  Bermuda,  Waller  (1973)  reported  "The 
majority  of  the  largest  individuals  [50  to  60  mm 
shell  height]  lie  free,  without  byssal  attachment, 
although  many  mature  individuals  attach  a  weak 
byssus  to  dead  shell  and  coral  fragments." 

A>i!^uciated  Orgarmms 

Setting,  growth,  and  survival  of  scallops  are 
positively  influenced  by  certain  sessile  plants  and 
animal  which  form  a  hospitable  habitat.  Young 
bay  scallops  attached  to  seagrass  (Belding,  1910), 
algae  (Marshall,  1960),  and  hydroids  (Zahl,  1969). 
Young  kelp  scallops,  Leptopecten  latiauratus 
were  found  in  the  interstices  of  erect  bryozoans 
(Brown  et  al.,  1967)  and  attached  to  colonial  in- 
vertebrates (particularly  hydroids)  and  algae 
(Turner,  Ebert,  and  Given,  1969).  According  to 
Dow  (1969),  young  sea  scallops  first  set  on  bryo- 
zoans that  are  attached  to  adult  scallop  shells 
and  at  a  larger  size,  attached  themselves  directly 
to  shells  or  bottom  debris.  Merrill  and  Edwards 
(1975)  noted,  however,  that  sea  scallop  spat  will 
set  "on  sedentary  branching  plants  and  animals, 
or-  any  other  hard  surface  on  or  above  the  ocean 
floor  which  offers  freedom  of  shell  movement  on 
all  sides." 

Before  the  inception  of  the  calico  scallop  spat 
monitoring  study,  most  calico  scallop  spat  had 
been  caught  by  trawl  or  dredge.  Under  these  cir- 
cumstances, spat  as  small  as  3.0  mm  shell  length 
were  found  attached  to  the  dead  shells  of  calico 
scallops  (Commercial  Fisheries  Review,  1962). 
Primary  setting  of  very  small  calico  scallop  spat 
on  filamentous  plants  or  animals  before  attach- 
ment to  mollusk  shells  was  not  reported. 
However,  spat  2.0  to  7.5  mm  shell  length  were 
among  the  epifauna  attached  to  the  shells  of  liv- 
ing calico  scallops  (Wells,  Wells,  and  Gray,  1964). 
In  addition,  calico  scallops  1  to  8  mm 
(presumably  in  shell  height)  were  reported  from 
plastic  floats  (Pequegnat,  Gaille,  and  Pequegnat, 
1967).  Attachment,  in  the  last  two  cases,  was  not 
necessarily  directly  to  the  shells  or  floats,  but 
perhaps  to  the  "pioneer"  fouling  organisms 
already  affixed.  Data  presented  by  Pequegnat, 
Gaille,  and  Pequegnat  (1967)  indicated  that  calico 
scallop  spat  occurred  in  greater  numbers  on 
plastic  floats  exposed  8  and  12  weeks  than  on 
floats  exposed  2  and  4  weeks,  and  that  the  floats 


October  30, 1979 

Vol.  94  (1) 

Table  4. 

Estimated    spawning   periods  of   calico  scallops  oft  Cape   Canaveral, 
July    1970  to    September   1971. 


Spat   trap  exposure 

Catch  of 

spat   size 

age   of    spat 

Estimated   spawning 

(per   day) 



7/21/70  - 






-   7/18/70 

8/26/70  - 








U/U/70  - 








1/06/71    - 








1/24/71    - 








1/24/71    - 








3/16/71    - 








4/20/71    - 








5/2  5/71    - 








6/26/71   - 








8/24/71   - 








1  Traps  «ere  located  at  Buoy  1  except  fo 
1/24/71  to  2/16/71,  which  were  at  Port 
about   0.6  m  above   the  ocean   floor. 

acquired    growths    of    hydroids    before    calico 
scallops  became  present. 

During  the  present  study,  filamentous  marine 
plants  and  animals  were  found  attached  to  array 
lines  and  spat  traps.  On  more  than  one  occasion, 
small  calico  scallop  spat  0.75  to  4.5  mm  shell 
height  (mostly  1.5  to  2.0  mm)  were  found  among 
attached  hydroids  (unidentified).  Attempts  at  sea 
to  determine  if  spat  were  byssally  attached  to  the 
hydroids,  rather  than  directly  to  array  lines  or 
spat  traps,  were  unsuccessful  because  of  rough 
sea  ronditions,  and  live  spat  had  detached  before 
microscopic  examination  could  be  made.  These 
observations  suggest,  however,  that  very  small 
calico  scallop  spat  may  utilize  filamentous  host 
organisms  for  setting,  perhaps  before  later  at- 
tachment directly  to  shell.  A  cycle  of  dependence 
may  be  operating,  since  certain  species  of 
hydroids  and  erect  bryozoans,  which  may  host 
calico  scallop  spat,  were  reported  by  Wells,  Wells, 
and  Gray  (1964)  as  common  among  epifauna  at- 
tached to  the  shells  of  living  calico  scallops. 

Most  organisms  in  the  spat  traps  apparently 

r   those  exposed   from   1/06/71  to  2/16/71   and 
Canaveral    R2  Buoy.      All   traps  were  positioned 

arrived  as  planktonic  larvae  and  included 
numerous  invertebrates  (coelenterates,  annelids, 
mollusks,  echinoderms,  crustaceans,  and 
tunicates)  and,  rarely,  fishes.  Calico  scallops  were 
generally  the  dominant  macroscopic  animals  in 
respect  to  biomass  and,  with  the  possible  excep- 
tion of  amphipods,  in  numbers.  Barnacles  were 
common  in  the  traps  and  were  sometimes 
attached  to  calico  scallop  spat.  At  least  some  bar- 
nacles attach  when  calico  scallops  are  young:  a 
barnacle  2.0  mm  diameter  at  its  base  was  found 
attached  to  a  spat  5.0  mm  shell  height. 

Ecological  .succession  in  the  spat  traps  may 
have  been  modified  or  hastened  by  the  effect  of 
the  filamentous  strands  of  polyethylene.  Contents 
of  one  spat  trap  exposed  for  only  11  days  in- 
dicated veiT  rapid  development  of  the  biofouling 
community  or  assemblage.  Included  were  121 
calico  scallop  spat  0.25  to  1.0  mm  shell  height,  125 
gastropod  mollusks,  and  250  amphii>)ds.  Tliere 
were  less  than  10  each  of  bivalve  mollusks  (other 
than  calico  scallops),  isopods,  copepods.  mysids, 
crabs,  and  polychaetes. 

Vol.M  (4) 

October  30, 1979 




The  abundance  and  size  of  calico  scallop  spat 
caught  during  successive  trap  exposure  periods 
were  used  to  estimate  the  season  and  intensity  of 
adult  spawning.  The  size  of  the  smallest  spat 
caught  during  each  exposure  period  (Table  4)  was 
related  to  age  (Figure  6).  For  spat  caught  during 
each  exposure  period,  spawning  was  estimated  to 
have  extended  from  16  days  before  the  trap  was 
first  exposed  to  the  date  the  trap  was  recovered, 
less  the  age  in  days  of  the  smallest  spat  caught. 
It  was  assumed  that  spat  abundance  primarily 
reflected  seasonal  spawning  intensity,  rather 
than  variations  in  survival  of  larvae  and  spat. 
Estimated  spawning  periods  from  July  1970  to 
October  1971  are  shown  in  Table  4.  Spawning  ap- 
parently occurred  during  all  seasons,  but  intensi- 
ty was  greatest  in  the  spring.  Following  low 
spawning  intensity  in  July,  and  lower  intensity 
from  August  into  December,  spawning  increased 
in  late  December  or  January  and  peaked  in 
March.  High  spawning  intensity  continued 
through  April  and  May,  followed  by  an  abrupt 
decrease  in  June  and  low  spawning  intensity  into 

There  is  no  direct  evidence  that  spat  setting  on 
the  Cape  Canaveral  grounds  are  entirely  or  par- 
tially the  first  generation  progeny  of  scallops 
spawning  in  that  area.  However,  the  spawning 
pattern  determined  from  seasonal  distribution 
and  abundance  of  spat  in  this  study  is  similar  to 
the  spawning  pattern  determined  from  ovarian 
color  changes  of  calico  scallops  on  the  Cape 
Canaveral  grounds  (Roe,  Cummins,  and  Bullis, 
1971;  Miller,  Allen,  Costello,  and  Hudson').  Fur- 
thermore, as  explained  previously,  water  circula- 
tion in  the  Cape  Canaveral  area  might  be  ex- 
pected to  retain  scallop  larvae  on  the  grounds  un- 
til setting  occurs. 

Spawning  of  calico  scallops,  similar  to  spawn- 
ing  of  other   bivalves,   is   influenced   by   water 

'  Miller.  G.  C.  D.  M.  Allen.  T.  J.  Costello.  and  .J.  H.  Hudson. 
Maturation  of  the  calico  scallop.  Argapecten  gibbus.  deter- 
mined by  ovarian  color  changes.  Manuscript  in  preparation. 
National  Marine  Fisheries  Service,  Southeast  Fisheries 
Center,  Miami  Laboratory,  Miami,  FL  33149. 

temperature  changes.  In  the  laboratory,  spawning 
of  ripe  calico  scallops  was  induced  by  raising 
water  temperatures  from  about  20°  to  2.5°C 
(Cxi.stello  et  ai,  1973),  but  these  temperatures  are 
not  necessarily  critical  for  spawning.  In  the 
natural  environment  off  Cape  Canaveral,  daily 
mean  temperatures  of  bottom  water  at  Buoys  1 
and  2  are  available  for  most  of  the  period  from 
March  28,  1970  to  August  24,  1971,  and  ranged 
(combined)  from  16.3°  to  26.9°C  (Leming,  1979). 
During  the  period  of  apparent  minimum  spawn- 
ing, August  through  November  1970,  bottom 
temperatures  at  these  sites  ranged  from  18.3° 
to  26.9°C,  while  during  apparent  maximum 
spawning,  March  through  May  1971,  tempera- 
tures fluctuated  between  16.9°  and  22.0°C. 
Temi^eratures  at  Buoys  1  and  2,  however,  were 
recorded  in  water  18  and  22  m  deep,  shoaler  than 
the  28  to  65  m  depths  where  most  of  the  scallops 
occur  off  Cape  Canaveral  (Allen  and  Costello, 
1972).  Therefore,  the  temperatures  at  Buoys  1  and 
2  often  varied  from  those  associated  wdth  the 
large  concentrations  of  scallops  in  deeper  water. 
On  the  shelf  off  Cape  Canaveral  there  was  a 
general  onshore  movement  of  18°C  bottom  water 
beginning  in  March  1971  (Leming,  1979).  This 
cold  water  passed  over  the  concentrations  of 
scallops  expected  to  be  mostly  ripe  during  March, 
April,  and  May  and  perhaps  triggered  successive 


The  spat  monitoring  techniques  used  in  this 
study  were  useful  in  determining  certain 
preliminary  information  concerning  the  biology 
of  the  calico  scallop.  However,  ecological  succes- 
sion and  other  alterations  with  time  in  an  ex- 
posed spat  trap  provide  a  continually  changing 
environment,  affecting  both  spat  setting  and  sur- 
vival. In  this  low-priority  study,  the  scheduling  of 
trap  exposure  was  governed  by  the  availability  of 
ship  time.  In  future  studies  to  measure  seasonal 
abundance  and  distribution  of  spat,  monitoring 
should  be  further  standardized  by  scheduling  trap 
exposure  for  relatively  short  time  periods  of 
uniform  length  and  interval  throughout  the  year. 
These  refinements  would  also  serve  to  more 
precisely  fix  spawning  time  and  provide  measures 


October  30. 1979 

Vol.94  (4) 

of  early  spat  growth  by  season.  Expansion  of  spat 
monitoring  over  wider  areas,  both  on  the  Cape 
Canaveral  grounds  and  on  the  Florida-Hatteras 
and  West  Florida  shelves,  would  provide  insight 
into  the  origin  of  the  larvae  and  the  relationship 
of  varying  water  temperature  regimes  to  spawn- 
ing, setting,  and  survival. 


I  thank  George  C.  Miller.  National  Marine 
Fisheries  Service.  Southeast  Fisheries  Center, 
Miami  Laboratory,  Miami.  Florida,  for  useful 
discussions  concerning  the  manuscript,  and  for 
the  photograph  for  Figure  4. 


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Dow.  R.  L.  1969.  Sea  scallop  fishery.  In  F.E.  Firth  (editor). 
The  encyclopedia  of  marine  resources,  p.  616-623.  Van 
No.strand  Reinhold  Co.,  New  York. 

Drummond,  S.  B.  1969.  Explorations  for  calico  scallop,  Pecten 
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Golikov.  A.  N.  and  0.  A.  Scarlato.  1970.  Abundance,  dvTiamics 
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of  organization  of  controllable  submarine  farms  at  the 
western  shores  of  the  Sea  of  Japan.  Helgol.  Wiss. 
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Marshall.  N.  1960.  Studies  of  the  Niantic  River,  Connecticut 
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October  30, 1979 


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Mag.  135:386-429. 


Francis  R.  Home  and  Steve  Mcintosh 

Department  of  Biology 

Southwest  Texas  State  University 

San  Marcos,  Texas  78666,  U.S.A. 


Enr)7-<»}me)ital  parameters  that  influence  the  di^tnhution  of  eight  mussels  in 
the  Blanco  River  of  Central  Texas  were  studied.  Tlie  effects  of  type  of  substrate, 
stream  flow  rate  and  physicochemical  features  on  mussel  distribution  were 
evaluated,  hut  emphasis  ivas  given  to  the  role  of  organic  enrichment  of  the  river 
by  a  city  sewage  treatment  plant.  From  tolerance  tests  to  ammonia  and  low  ox- 
ygen on  five  local  mussels  and  from  field  .studies,  the  follounng  remarks  can  he 
made  about  mussel  distribution  in  the  Blanco  River. 

(1)  Low  dissolved  o.tygen  levels  (0  -  (1.5  mg  (\  l~^j  proved  lethal  to  Jt7"/u  of  the 
mwssels  tested  in  seven  days. 

(2)  Levels  of  .5  mg  NH+4  -  NH.t'  (pH  7.S  to  H.O:  NH,  -  N  =  0.211  mg  -1)  were 
lethal  to  W%  of  the  mus.sels  tested  in  seven  days. 

(3)  Corbicula  manilensis  was  more  tolerant,  and  Amblema  p.  plicata  less 
tolemnt  than  the  other  mussels  tested  to  elevated  ammonia  and  low  oxygen  cim- 
centrations  associated  mth  .sewaj/e  emichment. 

iU)  Even  though  the  physicochemical  parametets  did  not  indicate  stressful  condi- 
tions on  the  d,ays  sampled,  mussels  of  the  Blanco  River  seemed  to  have  been 
adveisely  effected  by  emichment  from  the  secondary  sewage  treatment  plant  <f 
San  Marcos.  Fewer  mussels  were  found  downstream  from  the  sewage  phuit  than 
upstream,  even  where  the  river  baftmn.  depth,  and  flow  rates  ivere  similar. 


The  use  of  freshwater  mussels  (Bivalvia)  as 
aquatic  indicators  of  ecological  changes  brought 
about  by  agriculture,  mining  practices,  effluents 
from  industrial  and/or  domestic  disposal  plants 
has  not  been  studied  extensively.  Freshwiiter 
mussels  might  be  valuable  indicatm-s  of  Ixith  |)ast 

and  present  ecological  conditions  of  aquatic  en- 

For  the  following  reasons,  mussels  might  be 
especially  good  as  indicators  of  stream  conditions. 

(1)  Unlike  plankton  or  free  swimming  fauna, 
bivalves  as  benthic  invertebrates  usually  remain 
in  relatively  fixed  positions  in  streams  (Weber 


October  W,  1979 

Vol.9}  (1) 

(2)  Mussels  ain  directly  alisorb  nutrients,  sim- 
ple orpanic  connpounds  (Churchill  1916)  and 
various  pollutants.  Such  pollutants  might  be 
pesticides,  radioactive  materials  and  heavy 
metals  which  often  would  show  up  in  biologically 
magnified  concentrations  (Weber  1973;  Butler 
1965:  Fuller  1974:  Bedford  et  d.  1968;  Mathis 
and  Cummings  1973).  Bivalves  also  indirectly 
reflect  ecological  conditions  by  taking  up 
pollutants  by  feeding  from  the  bjusic  trophic 
levels  or  aquatic  food  chains  (Fuller  197 1). 

(3)  The  freshwater  mussels  (Unionacea)  have 
relatively  long  life  cycles,  up  to  17  years  and 
longer  (Williams  1969;  Bedford  et  d.  1968). 
Therefore,  their  community  and  population  struc- 
tures are  accumulatively  affected  by  environmen- 
tal perturbations  (Weber  1973). 

(4)  Unlike  periodic  chemical  analyses,  the  ben- 
thic  mussels  are  continuously  exposed,  except 
when  buried,  to  the  water  conditions  and  might 
reflect  variable  or  infrequent  discharges  of 
pollutants  (Weber  1973). 

Our  present  knowledge  is  insufficiently 
detailed,  however,  to  define  Unionaceae  or 
Sphaeriidae  (Pisidiidae)  as  pollutional  indicators 
in  chemical  terms  (Fuller  1974;  Ingram  1967).  A 
great  deal  of  work  needs  to  be  done  on  identify- 
ing the  reactions  of  bivalves  to  specific  natural 
factor's  in  the  environment,  and  on  the  reactions 
of  mollusks  to  pollutants  (Butler  1965). 

Recently,  Neel  and  Allen  (1964)  noted  the 
decimation  of  various  mussel  populations  in  the 
upper  Cumberland  Basin  by  coal  mine  acids, 
while  Charles  (1964)  found  that  very  heavy 
populations  of  mussels  have  been  virtually 
destroyed  by  brine  pollution  from  oil  wells.  Even 
potassium  has  been  suggested  to  regulate  the  sur- 
vival and  distribution  of  freshwater  mussels 
(Imlay  1973). 

Because  they  concentrate  certain  pollutants 
otherwise  not  detectable  in  water  or  sediments, 
mussels  have  been  utilized  as  indicators  of 
pesticide  and  metal  pollution  (Bedford  et  d.  1968; 
Mathis  and  Cummings  1973).  The  bivalves  concen- 
trated both  pesticides  and  metals  in  higher  con- 
centrations than  was  found  in  the  surrounding 
water,  but  contained  lower  levels  of  most  of  these 
toxic  compounds  than  occurred  in  sediments. 
Possibly  the  best  utilization  of  freshwater 
mussels  as  indicators  of  stream  conditions  is  as 

"indicators    of    the    biological    rec-overy    zone" 
(Simons  and  Reed  1973). 

The  purpose  of  the  current  study  was  to  explore 
the  environmental  parameters  that  influence 
distribution  of  mussels  in  the  Blanco  River.  Special 
emphasis  was  given  to  the  effects  of  organic  enrich- 
ment of  the  river  by  a  city  sewage  treatment 
plant.  Tolerance  tests  to  ammonia  and  low  ox- 
ygen on  five  species  of  local  mussels  were  con- 
ducted in  the  laboratory  in  an  atempt  to  evaluate 
such  enrichment. 


The  Blanco  River  is  located  at  the  headwaters 
of  the  Guadalupe  River  Basin  in  central  Texas. 
The  Blanco  River  flows  over  the  Edwards  Plateau 
and  joins  the  San  Marcos  River  approximately  4 
km  east  of  the  perimeter  of  the  plateau.  The  Ed- 
wards Plateau  is  composed  of  uplifted  limestones 
that  contribute  to  the  natural  calcareous  hard- 
ness of  the  Blanco  River.  At  the  Kyle  sampling 
station  the  mean  annual  flow  for  a  19  year 
sampling  period  was  4.3  m^  sec"'  (U.S.G.S.  1976). 
At  the  Kyle  gauging  station,  about  9  km 
upstream  from  the  study  area,  no  flow  levels  oc- 
curred in  the  summers  of  1956,  1963,  19(>4  and 
twice  in  1971  (U.S.G.S.  1976).  Except  during 
periods  of  flooding,  the  lower  portion  of  the 
Blanco  River  is  usually  transparent  enough  for  a 
visual  analysis  of  the  substrate. 

The  drainage  basin  of  the  Blanco  River  above 
the  Kyle  sampling  station  is  1,(X)7  sq.  km.  and 
contains  little  arable  land.  Most  of  the  basin  is 
sparsely  populated,  and  agriculture  consists 
mainly  of  grazing  with  only  limited  crop  farming 
on  the  rocky  terrain.  After  the  Blanco  River 
leaves  the  plateau,  the  river  traverses  a  more 
populated  area  where  crop  farming  predominates. 

Sampling  areas  on  the  Blanco  River  were 
located  between  29°55'— 29°5r  latitude  and 
97°55'— 97°54'  longitude.  The  study  area  consisted 
of  a  6  km  stretch  of  the  Blanco  River  located  just 
upstream  of  the  confluence  of  the  San  Marcos 
River  (Fig.  1).  A  secondary  sewage  treatment  ef- 
fluent enters  the  Blanco  River  approximately  2 
km  downstream  from  the  headwaters  of  the  study 
ai^a.  The  sewage  effluent,  except  under  very  low 
flow  conditions,  is  diluted  naturally  by  a  side 
channel  of  the  river  before  it  reaches  the  main 
stream.    In    the    faster    moving    waters    of   the 

Vol.94  (4) 

October  30, 1979 


FIG.  1.  Location  of  sampling  sites  on  the  Blanco  River.  Texas. 

diluted  side  channel,  toxicity  study  areas  were 
established  about  50  m  before  and  after  the  point 
of  entry  of  the  sewage.  Three  sampling  stations 
for  physicochemical  analyses  of  the  river  were 
located  (1)  about  50  m  above  (Station  3),  (2)  200 
meters  (Station  4)  and  (3)  2  kilometers  below 
(Station  6)  the  site  where  the  sewage  effluent 
enters  the  river  (Fig.  1 ). 

Qualitative  and  Quantitative  Determinations 

Qualitative  and  quantitative  mussel  counts 
were  performed  at  mid-day  by  visual  inspection 
while  wading  or  scuba  diving  in  the  deeper  pools. 
The  entire  study  area  was  quantitatively  sampled 
for  freshwater  mussels.  Three  quantitative  counts 
were  made  at  stations  above,  and  two  quan- 
titative counts  below  the  sewage  effluent  (Fig.  1). 
Quantitative  counts  were  made  in  10  m^  areas 
utilizing  ten  one  meter  transects.  After  identify- 

ing and  recording  the  specimens,  they  were  lifted 
from  the  substrate  to  prevent  duplications.  Only 
those  individuals  exposed  or  actively  siphoning  in 
the  substrate  were  utilized  in  the  quantitative 

Mussel  specimen  identifications  were  made 
utilizing  the  taxonomic  keys  of  Burch  (1973), 
Murray  (1%2;  1968),  Simpson  (1913)  and  Strecker 
(1931).  Identifications  were  checked  and  verified 
by  Dr.  H.  D.  Murray  of  Trinity  University  in  San 
Antonio,  Texas,  and  Dr.  David  Stansbery  of  Ohio 
State  University  in  Columbus,  Ohio.  Specimen 
were  deposited  at  Ohio  State  University  (Collec- 
tion Numbers  OSUM:  1976:  352-361). 

Tolerance  Tests 

Specimens  utilized  in  the  tolerance  tests  were 
collected  in  central  Texas  near  the  study  area. 
The  specimens  were  then  placed  in  aerated 
aquaria  for  a  minimum  of  five  days  for  acclima- 
tion to  laboratory  conditions.  During  the  period 
of  acclimation  and  testing,  the  experimental  and 
control  specimens  were  not  fed.  Before  being 
utilized  in  the  toxicity  tests  each  laboratory 
specimen  was  washed  and  scrubbed  to  remove 
adhering  organisms.  The  ventral  margins  of  the 
bivalves  were  notched  with  a  triangular  file  so 
that  the  bivalves  would  be  constantly  exposed  to 
the  stressors.  At  least  eight  specimens  of  each 
species  were  utilized  in  the  toxicity  tests. 

The  chlorine  content  of  the  tap  water  used  in 
the  experiments  ranged  from  0.2  -  0.4  mg  1"'  and 
was  removed  from  the  test  waters  by  aeration  or 
bubbling  nitrogen.  The  total  alkalinity  of  the 
water  varied  from  200  to  250  mg  1"'  and 
depended  upon  the  stressor(s)  utilized  The  total 
alkalinity  of  water  from  which  the  organisms 
were  collected  varied  from  150  to  200  mg  1"'.  The 
temperature  of  the  experiments  was  ambient 
room  temperature  which  was  usually  between 
24°— 26°  C.  The  hydrogen  ion  concentration  (pH) 
ranged  between  7.8  and  8.2  during  the  laboratory 
experiments.  At  an  average  pH  of  8.0  a  solution 
containing  ammonia  (NH-I-4  -NH3)  would  consist 
of  94.7%  ammonium  ions  and  5.3%  ammonia  gas 
(NH3).  In  this  manuscript  the  term  ammonia 
refers  to  both  the  ionic  and  gaseous  form,  even 
though  the  gaseous  ammonia  is  the  toxic  form. 

At  no  time  were  moi'e  than  four  larger  mussels 
used    in    a    single    experiment.    The    bivalves 


October  30. 1979 

Vol.  94  (4) 

Table  1.   Substrate  related  distribution  of  freshwater  mussels  in  the  Blanco  River. 


Stream  Bottom 





Sand     Silt-mud 

Amblema  £. 







Lampsilis  a. 






+++  =  More  than  S/m^ 

++  =  1-5/m^ 

+  =  Less  than  l/m^ 

-  =  Not  Found 

Amblema  p.  plicata  (Say,  1817),  Anodonta  im- 
hecillis  (Say,  1829),  Corbdcula  manilensis  (Philip- 
pi,  1844),  Ci/Honaias  tampicnen.'iis  (Lea,  1838), 
Toxolasma  texasensis  (Lea,  1857)  (^Cairunculina 
parva  texasensis)  were  subjected  to  laboratory 
tolerance  tests  for  168  hours.  Specimen  were 
removed  from  the  testing  apparatus  after  failure 
to  respond  to  physical  stimuli  by  closure  of  the 
valves.  Death  was  established  when  the  mussels 
did  not  respond  by  attempted  closure  when  their 
valves  were  partially  pried  apart. 

Low  oxygen  tolerance  tests  (0  -  0..5  mg  0  2  1  '') 
were  performed  in  a  modified  8  liter  desiccator 
with  a  regulated  water  flow  of  about  300  ml 
hr.''.  A  16  liter  reservoir  of  water  was  deo.x- 
ygenated  by  bubbling  prepurified  nitrogen  gas. 
The  deoxygenated  water  was  mixed  with  a 
magnetic  stirrer  and  forced  through  the  testing 
apparatus  with  low  N2  pressure.  Water  samples 
for  chemical  analyses  were  taken  from  the  testing 
apparatus  by  removal  and  subsequent  replace- 
ment of  standard  biochemical  oxygen  demand 
(BOD)  bottles  that  were  situated  before  and  after 
the  specimen  container.  By  maintaining  the  flow 
at  least  300  ml  hr"'  the  dissolved  oxygen  (DO) 
levels  of  the  incoming  and  outflowing  waters  of 
the  specimen  container  were  similar. 

In  the  combination  high  ammonia  and  low  ox- 
ygen tolerance  tests  the  water  was  deoxygenated 
first  and  ammonia  then  added  to  the  above 
testing  apparatus.  In  both  the  combination  high 
ammonia-low  oxygen  and  high  ammonia 
tolerance  tests,  ammonia  levels  of  5  ±  0.5  mg  1"' 
(NH^  -N  =  0.26  mg  l"')  were  obtained  by  the  ad- 
dition of  ammonium  bicabonate.  Bunkhalter  and 
Kaya  (1977)  estimated  0.25  mg  NH^-Nl"'  to  be 
the  incipient  lethal  threshold  concentration  for 
rainbow  trout  fry. 

High  ammonia  tolerance  tests  were  performed 
in  8  liters  of  aerated  tap  water  in  covered 
aquaria.  Samples  for  chemical  analyses  were 
made  by  removal  and  subsequent  replacement  of 
similar  amounts  of  water  from  the  aquaria. 

Tlie  tolerance  tests  in  the  Blanco  River  were 
performed  in  a  side  channel  which  contained 
diluted  .sewage.  The  bivalves  Amblema  p.  plicata, 
Anadonta  imbecillis.  Curbicula  manilensis  and 
Cjfiionaias  tampicoensis  were  put  under  stress. 
The  mussels  were  placed  in  cages  of  1/4  inch 
square  mesh  screen  which  were  partially  buried 
in  the  gravel  substrate.  The  controls  were  located 
50  m  above  the  point  of  entry  of  the  sewage  and 

Vol.  94  (4) 

October  30, 1979 


were  placed  in  a  similar  substrate.  The  side  chan- 
nel toxicity  tests  were  performed  for  one  month 

Statistical  analyses  of  the  toxicity  studies  were 
performed  by  single  factor  analysis  of  variance 
and  after  hypothesis  rejection  analyses  were 
followed  by  the  Student  Newman  Kuels  tests  for 
differences  in  population  ranges  (Zar  1974).  The 
survival  times  in  hours  were  used  as  the  observa- 
tions in  the  statistical  tests.  Since  the  maximum 
utilizable  value  for  sui-vival  time  was  sometimes 
limited  by  the  length  of  the  toxicity  test,  inter- 
pretations of  the  above  statistical  analyses  were 
Phymcochemical  A  nalyses 

Water  samples  were  taken  with  1  liter 
polyethylene  bottles  0.3  m  below  the  surface  on 
sunny  mid-day  periods.  Water  temperature  was 
taken  at  the  same  time  0.3  m  below  the  surface 
in  shaded  areas.  Qilorine  levels  were  determined 
in  the  field.  Stream  velocities  were  measured 
with  a  U.S.G.S.  Pigmy  current  meter.  Gilorine 
levels  were  determined  in  the  field,  whereas 
samples  for  pH,  alkalinity,  DO,  NH+4  -N,  BOD5 
and  total  mercury  were  analyzed  wdthin  forty- 
five  minutes  of  collection  in  the  laboratory. 
Samples  for  the  determinations  of  Kjeldhal 
nitrogen,  total  dissolved  phosphate-phosphorus, 
and  potassium  were  stored  at  -20°C  and  analyses 
were  conducted  within  three  hours  of  collection. 
Chemical  analyses  of  water  were  performed  ac- 
cording to  Standard  Methods  for  the  Examina- 
tion of  Water  and  Wastewater  (A.P.H.A.  1975). 

Sediment  analyses  were  performed  utilizing 
the  modified  Wentworth  grade  classification 
(Home  and  Mclntyre,  1971  and  Weber,  1973).  The 
substrate  was  scooped  into  a  container  placed 
just  downstream  and  analyzed  using  U.S.  Stan- 
dard sieves.  Hydrogen  ion  concentrations  were 
determined  with  a  standardized  Beckman  Expan- 
domatic  pH  meter.  Total  alkalinity  analyses  were 
performed  by  titration  with  0.02N  H2SO4  to  a  pH 
of  4..5.  Dissolved  oxygen  determinations  were  per- 
formed utilizing  the  alkali-azide  modification  of 
the  Winkler  method.  Ammonia  nitrogen  analyses 
were  made  by  distillation  of  the  ammonia  into 
boric  acid  followed  by  nesslerization.  Kjeldahl 
nitrogen  determinations  were  made  by  sample 
digestion  followed  by  distillation  and  nessleriza- 
tion.  Total   dissolved    phosphate-phosphorus 

samples  were  first  filtered  through  0.45  micron 
filters  and  then  treated  to  persulfate  digestion 
and  the  color  developed  by  the  ascorbic  acid 
method.  Chlorine  levels  were  determined  utilizing 
the  orthotolidine  colorimetric  methods.  Total 
mercury  analyses  were  performed  by  the  cold 
vapor  technique  using  a  mercuiy  analyses  system 
connected  to  an  atomic  absorption  spectro- 
photometer. Total  potassium  ion  determinations 
were  made  utilizing  an  atomic  absorption  spec- 


Qualitative  Sampliny  and  Species  Distribution 

Living  specimens  of  eight  species  of  freshwater 
mussels,  and  shells  of  Amdonta  g.  grandis  (Say, 
1829)  and  Lampsilis  anodontoides  fallaciosa 
(Smith,  1899),  were  collected  in  the  Blanco  River 
study  area  (Table  1). 

The  type  of  stream  bottom  and  the  corre- 
sponding flow  patterns  seemed  to  limit  the 
distribution  and  perhaps  the  abundance  of  some 
of  the  species  (Table  1).  Local  geologic  formations 
(recent  alluvium)  and  periodically  high  stream 
velocities  created  a  bottom  composed  of  a 
gravel-cobble  substratum  in  the  faster  flowing 
portions  of  the  stream.  Only  on  the  periphery  of 
the  larger  pools  where  the  current  was  slow  was 
a  mud-silt  bottom  found  (Fig.  1).  All  species  col- 
lected in  the  river  were  present,  although 
sometimes  sparsely,  in  mud-silt  substrates. 

Individuals  having  relatively  heav>'  shells,  such 
as  Quadrula  petrina  and  Amblema  p.  plicata, 
were  the  only  species  found  in  water's  with 
average  stream  velocities  of  1  m  sec"'  or  greater. 
In  these  waters  the  bottom  was  typically  com- 
posed of  cobbles  with  some  boulders  and  gravel 
present.  Although  Corbicula  manilensis  has  a 
relatively  thick  shell  its  small  size  probably 
limits  it  from  occurring  in  the  swiftest  waters 
(Table  1). 

Freshwater  mussels  with  shells  of  intermediate 
thickness  such  as  Ciirtonnias  tampicoensis.  Lamp- 
silk  a.  anodontoides  (Lea,  1834)  and  Lampsilis 
bracteata  (Gould,  1855)  generally  were  found  in 
regions  of  intermediate  stream  velocities  (0.5  -  1 
m  sec"')  where  the  usual  bottom  comp<jsition  was 
coarse  and/or  medium  sized  gravel.  The  very  thin 
shelled  Anodonta  imbecillis  and  the  small  sized 
Toxolusma   texasensis   were   restricted   to   areas 


Octobei-  :10, 1979 

Vf.l.  94  (4) 

with  the  finast  types  of  substrate  material  (Table 
1).  and  both  were  rarely  found  in  the  river. 

Ph  yiiicochemical  Parameters 

During  the  sampling  period  from  July,  1976,  to 
June,  1977,  the  minimum  flow  was  1.5  m^  sec"' 
and  the  ma.\imum  flow  was  about  112  m^  sec"'  at 
the  Kyle  gauging  station.  Unlike  previous  years 
very  low  or  no  flow  periods  did  not  occur  during 
the  sampling  year.  Water  temj^eratures  varied 
from  11.5°C  in  January,  1977,  to  31.0°C  in  August, 
1976.  Secchi  disc  transparency  varied  from  0.8  m 
to  2.1  m  in  the  Blanco  River,  (^nerally,  trans- 
parency increased  during  low  flow  periods  and 
decreased  during  high  flow  periods. 

The  secondary  sewage  plant  adjacent  to  the 
Blanco  River  usually  received  less  than  30%  of 
the  total  sewage  load  of  San  Marcos.  The  mean 
flow  through  the  sewage  treatment  plant  for  the 
twelve  month  sampling  period  was  0.84  million 
gallons/day  (mgd)  with  extremes  of  about  0.05  to 
1.1  mgd. 

For  June,  1977,  average  effluent  values  for  the 
treatment  plants  and  the  diluted  sewage  of  the 
side  channel  are  given  in  Table  2.  Also  for  June 
the  sewage  enriched  side  channel  of  the  Blanco 
River  (Fig.  1)  had  a  total  flow  of  approximately 

0.1  m^  sec"'  of  which  about  20  -  50%  was  sewage 
effluent,  depending  upon  the  amount  of  effluent 
discharged.  During  the  same  period,  the  Blanco 
River  received  an  average  of  110  kg  BOD,  day"', 
90  kg  potassium  day"',  50  kg  of  ammonia-N  day"' 
and  9  kg  of  total  phosphate-phosphorus  day"'  . 
The  secondary  treatment  plant  received  waste 
from  only  the  northeast  portion  of  San  Marcos. 

Total  mercury  analyses  for  the  sewage  effluent 
and  water  samples  from  the  Blanco  River  in 
March,  1977,  were  below  detectable  limits  (less 
than  one  microgram  1"').  Chlorine  also  was  not 
detectable  (less  than  0.1  mg  1"')  in  the  enriched 
side  channel.  Chemical  parameters  which  were 
monitored  at  Stations  3,  4  and  6  (Fig.  1)  are 
presented  in  Table  2.  Where  the  sewage  effluent 
entered  the  river,  all  parameters  increased,  ex- 
cept dissolved  ox>'gen  and  pH.  The  largest  in- 
creases occurred  with  ammonia  and  total 
dissolved  phosphate  which  increased  300%  and 
100%,  respectively.  At  the  sampling  station 
located  2  km  downstream  from  the  treatment 
plant  (Site  6),  all  parameters  were  more  similar 
to  the  uncontaminated  waters  above  the  sewage 
effluent.  Only  dissolved  oxygen  returned  to  its 
upstream     (Site    3)    concentration     at    the 

Table  2. 

Water  chemistry  determinations  for  the  sewage  effluent  and  diluted 
sewage  in  Blanco  River  side  channel. 

Parameter  (mg  1~1) 

Sewage  effluent 

Side  channel 
(diluted   sewage) 

BOD  5 


Dissolved  oxygen 


pH  (units) 


Total  alkalinity 

Total  dissolved 








Vol.  91  (1) 

October  30, 1979 


Table  3. 

Water  chemistry  determinations  for  the  Blanco  River. 

Twelve  month  average  (range) 

Parameter  (mg  1   ) 

(Site  3) 

(Sewage  Plant) 

(Site  6) 

BOD  5 

(0.9  -  2.2) 

(1.0  -  5.0) 

(1.0  -  2.6) 

Dissolved  oxygen 

(6.75  -  10.42) 

(6.88  -  10.35) 

(7.42  -  10.37) 

4    3 

(0.01  -  0.05) 

(0.01  -  0.27) 

(0.01  -  0.14) 

Organic  -  N 

(0.09  -  0.36) 

(0.09  -  0.63) 

(0.08  -  0.49) 


(1.70  -  2.70) 

(1.85  -  2.85) 

(1.85  -  2.78) 

pH  (units) 

(7.74  -  8.02) 

(7.74  -  8.02) 

(7.75  -  8.02) 

Total  alkalinity 

193  OO 
(165  -  212) 

(170  -  224) 


(170  -  224) 

Total  dissolved 


(0.04  -  0.26) 

(0.05  -  0.49) 

(0.04  -  0.72) 

downstream  station  (Site  6).  The  nutrient  levels 
of  ammonia-N  best  indicated  the  enrichment  of 
the  sewage  effluent  upon  the  Blanco  River  (Table 

Tolerance  Tests 

The  laboratory  tolerance  tests  were  chosen 
because  they  measured  parameters  that  were 
potentially  toxic  to  freshwater  mussels  and  which 
may  result  from  organic  enrichment.  Since  the 
laboratory  tests  lasted  only  seven  days,  highly 
stressful  conditions  were  needed  for  definitive 
results.  Nevertheless,  the  concentrations  chosen 
were  environmentally  realistic.  During  the  labor- 
atory tolerance  tests,  it  was  frequently  observed 
that  the  more  tolerant  species  had  their  shells 
tightly  shut,  while  the  least  tolerant  species 
usually  continued  siphoning  or  had  their  mantles 

Tlie  exotic  asiatic  clam  (Corhicula  manilensis) 
demonstrated  greatest  survival  to  low  oxygen 
conditions  (Table  4).  The  native  mussels,  Amxlon- 
ta  imhecillis  and  ToXDlasmn  texaserms,  also  had 
relatively  high  survival  capacities  to  low 
dissolved  oxygen,  whereas  Cyrtonauu^  tampicoen- 
sLs  and  Amblema  p.  plicata  had  the  lowest  sur- 
vival   tolerances.    Amblema    p.    plicata    had    a 

significantly  lower  survival  tolerance  to  low 
dissolved  oxygen  (Table  5).  Although  the  four 
other  species  exhibited  large  differences  in  their 
survival  capacities  (Table  4),  they  were  not 
significantly  different  at  95%  confidence  limits 

TdXdlasma  texxmensi^  demonstrated  the  highest 
survival  capacity  during  the  aerated  high  am- 
monia tests  (Table  6),  whereas  Arwdonta  im- 
beciUis  and  Amblema  p.  plicata  had  the  lowest 
tolerance  to  high  ammonia  concentrations.  Due  to 
their  frequent  gaping,  snapping  of  valves  and  ex- 
trusion of  glochidia  when  gravid,  Anodnnta  im- 
becillis  appeared  to  be  the  most  stressed  species. 
All  species  frequently  secreted  mucous  at  the 
beginning  of  the  aerated  ammonia  experiments. 
The  interspecific  survival  capacities  were  not 
statistically  different  at  95%  confidence  limits  for 
the  mussels  in  high  ammonia  (Table  5). 

In  the  combination  high  ammonia— low  oxygen 
tolerance  tests,  Corbicula  manilensis  again 
demonstrated  the  highest  survivorship  (Table  7). 
No  apparent  synergistic  effects  were  detected  in 
the  combination  high  ammonia— low  dissolved  ox- 
ygen tests.  Interspecifically,  Amblema  p.  plicata 
had  significantly  lower  survival  tolerance  and 
Corhicvla    manilensis    had    significantly    higher 


October  30. 1979 

Vol.  94  (4) 

tolerance  as  compared  to  mast  of  the  other 
species  (Table  5). 

Survival  of  the  mussels,  e.xcept  Corbinda 
manilensnn  in  the  combination  low  o.xygen— high 
ammonia  tests,  appeared  to  be  related  to  the 
mussel's  tolerance  to  one  of  the  two  most  .stress- 
ful parameters.  Intraspecfic  suiTival  capacities  in 
the  laboratory  tolerance  tests  were  not  signifi- 
cantly different  at  the  95%  confidence  limit. 

The  tolerance  tests  in  diluted  sewage  again 
demonstrated  that  Corbicula  manilensis  had 
significantly  higher  survival  capacities  (Table  5 
and  8).  Amhlema  p.  plicutu  had  significantly 
lower  tolerance  to  the  diluted  sewage,  while 
Criitonnkui  tnmpicoemis  and  Anodonta  imbecillis 
exhibited  intermediate  survival  capacities  that 
were  not  significantly  different  from  each  other. 

The  levels  of  potential  toxicants  in  the  sewage 
side  channel  are  given  in  Table  2.  Ammonia  and 
{wssible  potassium  were  found  at  ptjtentially 
lethal  concentrations.  However,  the  measured 
daylight  and  nocturnal  oxygen  levels  did  not  ap- 
pear near  the  lethal  range  nor  potentially 
stressful  during  the  tolerance  tests.  Although  low- 
oxygen  levels  may  not  have  been  present  in  the 
sewage  side  channel  (Table  2),  the  relative 
tolerance  of  the  mussels  was  comparable  to  their 
.survival  capacities  in  the  combination  low  o.xygen 
—high  ammonia  tolerance  tests  (Tables  .5,  7  and 

Quantitative  Samples 

Quantitative  sampling  sites  were  chosen  in 
areas  with  similar  substrates  at  mid-stream  loca- 
tions in  both  the  slow  and  fast  moving  waters. 
The  substrate  composition  shown  in  Table  9  is 
from  faster  moving  waters  (0.3  -  1.5  m  deep),  but 
even  at  the  sampling  stations  in  the  slower  mov- 
ing waters  (1  -  4  m  deep)  more  than  90%  of  the 
substrate  was  composed  of  fine  gravel  or  larger. 
All  quantitative  sampling  sites  were  located  in 
areas  containing  relatively  high  populations  of 
freshwater  mussels.  Therefore,  data  presented  in 
Table  10  is  representative  of  the  more  dense 
mus.sel  populations  of  the  Blanco  River.  Marked 
differences  were  noted  in  the  number  of  species 
and  the  populations  of  mussels  above  and  below 
the  point  of  entry  of  the  sewage  effluent  (Table 
10).  Initially  during  the  study  period  large 
numbers  of  mussels  were  found  in  the  river  im- 
mediately below  the  sewage  effluent  (Fig.  1).  At 
the  end  of  the  study  period  in  July,  1977,  very 
few  mussels  were  found  alive  at  this  site.  The 
large  numbers  of  mussels  initially  found  in  the 
uppermost  portion  of  the  enriched  study  area 
may  have  been  transported  by  floods  from  a  large 
bed  of  mussels  found  just  upstream  at  Site  3  (Fig. 

Of  the  native  species.  Amblema  p.  plicata  and 
Qumlnda  petrina  were  the  most  abundant.  The 
asiatic    clam    (Corhicida    manilensis)    was    not 

Table  4.   Percentage  survival  in  low  oxygen  concentrations  (0-0.5  mg  O^  1  ■'■)  . 

Species  (Number  used) 

55  hr 

110  hr 

165  hr 

Amblema  p.  plicata 

Anodonta  imbecillis 

Corbicula  manilensis 

Cyrtonaias  tampicoensis 

Toxolasma  texasensis       (8 














Vol. m  (I) 

October  30, 1979 


Table  5. 

Statistical  analyses  of  tolerance  tests  (SNK)  for  interspecific  mean 
survival  times. 


Low  0-) 

Tolerance  Test 

High  NH3 

Low  O2  +  High  NH3 

Diluted  Sewage 

1)  Amblema  p. 

2)  Anodonta 

irabeci  His 



3)  Corbicula 

manilensis      +S(1) 

4)  Cyrtonaias 

tampicoensis    +S(1) 

5)  Toxolasma 

texasensis      +S(1) 









+  3(1) 






3  =  Significantly  different  at  95%  confidence  interval  (-3  =  lower;  +3  =  higher). 
NS  =  Not  significantly  different  at  95%  confidence  interval. 

noticeably  present  in  the  study  area  in  the  spring 
or  summer  of  1976.  However,  immature  Corbinda 
manilensis  were  found  about  7  km  upstream  of 
the  study  area  in  the  spring  of  1976.  Immature 
specimens  were  first  evident  in  the  study  area  in 
the  spring  of  1977.  Corbicula  manilensis  was 
found  in  much  higher  concentrations  above  the 
sewage  effluent  than  given  in  Table  9.  Densities 
of  up  to  50  m"^  of  small  individuals  were  found  in 
the  uncontaminated  headwaters  of  the  Blanco 
River  side  channel  (Fig.  1).  The  highest  numbers 
of  Corbicula  manilensis  occurred  in  sand-fine 
gravel  substrates.  No  living  specimens  of  Cor- 
bicula manilensis  were  found  below  the  entrance 
of  the  sewage  effluent  in  the  Blanco  River. 


From  the  previous  records  of  Strecker  (1931) 
all  of  the  species  collected  in  the  present  study, 
except  the  exotic  asiatic  clam  (Corbicula  manilen- 
sis), have  been  present  in  the  Guadalupe  River 
drainage  for  many  years.  Since  Lainpsilis 
bracteata  is  still  present  in  the  Guadalupe  and 
San  Antonio  River  drainages,  and  Quadrula 
aurea  (Lea,  1859)  is  also  present  in  the 
Guadalupe  River  drainage,  the  continued  ex- 
istence of  these  species  may  not  be  threatened. 

Athearn  (1970)  has  considered  both  Lampsilis 
bracteata  and  Quadrula  aurea  as  rare  and  en- 
dangered in  central  Texas. 

Some  species  of  mussels  are  limited  in  their 
distribution  by  the  type  of  stream  bottom.  For 
example,  mussels  of  the  genus  Anodonta  and  Lep- 
todea  fragilis  were  only  rarely  found  in  rocky 
substrates  (Murray  and  Leonard,  1962).  In  the 
Blanco  River  Anodonta  imbecillis  and  other 
species  with  relatively  thin,  light  weight  shells 
did  not  occur  in  swift  waters  with  coarse 
substrates.  This  might  be  due,  in  part,  to  their 
physical  displacement  and/or  destruction  by  the 
shearing  forces  in  faster  waters. 

Considering  the  rapid  dissemination  and 
population  growth  of  Corbicula  manilensis.  their 
abundance  in  the  upper  half  of  the  study  area  in 
1977  was  not  suprising  even  though  none  were 
noted  in  1976.  Gardner  et  al.  (1976)  observed  that 
the  population  of  Corbicula  manilensis  in  the 
Altamaha  River  (Georgia)  increased  from  a 
minimum  of  0/m^  in  1971  to  a  maximum  of 
10,000/m^  in  1974.  Corbicula  manilensis  main- 
tains a  distinctive  reproductive  advantage  over 
the  usually  dioecious,  slow  growing,  glochidial- 
producing  native  freshwater  mussels.  Corbicida  is 


October  30, 1979 

Vol.  94  (4) 

monoecious,  incubates  its  free-living  larvae  and  is 
sexually  mature  in  less  than  one  year  (Gardner 
et  al.  1976). 

The  physicochemical  parameters  measured 
from  July,  1976,  to  June,  1977,  for  the  Blanco 
River  were  similar  to  those  found  from  other 
parts  of  the  Guadalupe  River  drainage  (Hannan 
et  al.  1973;  Young  et  al.  1972).  The  large  in- 
creases of  ammonia-N  (300%)  below  the  point  of 
entrance  of  the  sewage  effluent  into  the  river 
suggested  organic  enrichment  of  the  stream.  Am- 
monia values  often  are  a  good  index  of  changes  in 
trophic  status  of  streams  that  have  been  in- 
fluenced by  excessive  enrichment  by  organic 
wastes  (Ellis  1937). 

Although  pronounced  changes  in  the  water 
chemistry  were  found  below  the  point  of  entrance 
of  sewage  effluent  into  the  river,  none  of  the 
parameters  measured  were  at  concentrations 
known  to  be  toxic  or  harmful  to  freshwater 
mussels.  Upon  consideration  of  the  sources  of 
waste  entering  the  secondary  treatment  plant,  ex- 
cessive pollution  by  heavy  metals  or  pesticides 
was  not  likely.  The  lack  of  measurable  flow  in 
the  Blanco  River  as  reported  by  the  Kyle  gauging 
station  during  previous  dry  periods  (U.S.G.S. 
1976),  however,  could  increase  the  levels  of  poten- 
tial toxicants  to  concentrations  equal  to  or 
greater  than  the  levels  found  in  the  diluted 
sewage  side  channel.  When  the  Blanco  River 
stops  flowing,  as  it  does  every  few  years,  the 

sewage  is  not  diluted  when  it  enters  the  river 
and  is  then  the  primary  source  of  water  below 
the  sewage  plant. 

The  levels  of  ammonia-N,  potassium  and  noc- 
turnal dissolved  oxygen  could  be  potential 
hazards  for  the  mussels  during  such  low  flow 
periods.  Imlay  (1973)  found  potassium  levels  of  11 
ppm  to  be  toxic  in  36-52  days  to  90%  of  the 
freshwater  mussels  tested,  and  for  long  term  sur- 
vival. Imlay  (1973)  postulated  that  potassium 
levels  should  be  no  higher  than  4  to  10  mg  T'.  It 
is  doubtful  that  potassium  would  be  a  problem  in 
the  Blanco  River.  In  contrast,  it  is  well  known 
that  nocturnal  dissolved  oxygen  deficiencies  also 
can  be  critical  in  determining  stream  distribution 
of  organisms  (Gaufin  and  Tarzwell  1952). 
Organically  rich  pools  or  slow  moving  waters  in 
the  Blanco  River  might  experience  extreme  fluc- 
tuation in  O2  concentration,  especially  at  the 
mud-water  interface.  Cx)nsidering  the  levels  of 
potential  toxicants  (ammonia,  low  O2  and 
potassium)  in  the  Blanco  River,  as  demonstrated 
by  their  values  in  the  diluted  sewage  side  chan- 
nel, ammonia  is  probably  the  most  lethal  stressor 
to  mussels  during  the  low  flow  periods. 

The  depletion  of  dissolved  oxygen  that  results 
from  sewage  enrichment  has  been  proposed  as  the 
principle  stressor  influencing  molluscan  survival 
(Ingram  1957).  Ellis  (1937)  stated  that  juvenile 
mussels  are  very  sensitive  to  low  oxygen  concen- 
trations and  that  adults  usually  become  quiescent 

Table  6. 

Percentage  survival  in  high  ammonia  (5  mg  NH  +NH  -N) 

4    3 

Species  (Number  used) 

55  hr 

110  hr 

165  hr 

Amblema  £.  plicata 

(  9) 




Anodonta  imbecillis       (  9) 




Corbicula  manilensis       (14) 




Cyrtonaias  tampicoensis    (10) 




Toxolasma  texasensis       (10) 




Vol.  94  (4) 

October  30, 1979 


Table   7.       Percentage   survival    in    low  oxygen    and   high   anunonia 

i   - 

(0-0.5    rag   O2    1~      +    5    mg   NH>NH^-N) 

Species  (Number  Used) 

55   hr 

110    hr 

165   hr 

Arnbleraa   p.    plicata 

(  8) 



Anodonta  imbecillis 




Corbicula  manilensis 





Cyrtonaias  tampicoensis     (10) 



Toxolasma  texasensis 




when  oxygen  levels  are  at  or  below  20%  satura- 
tion. However,  mussels  generally  are  more 
tolerant  of  low  O2  levels  than  freshwater  fishes. 
One  of  the  more  tolerant  of  the  freshwater  fishes, 
the  carp,  survives  only  a  short  time  in  water  con- 
taining 0.71  mg  O2  1'.  In  contrast,  in  the  low  O2 
tolerance  tests  (0  -  0.5  mg  O2  1"')  about  53%  of 
the  mussels  tested  in  this  study  survived  for 
seven  days  (Table  4). 

During  the  laboratory  tolerance  tests,  the 
mussels  that  did  not  have  their  valves  closed  for 
extended  periods  were  more  senstive  to  stressors 
(NH3  and/or  low  O2).  A  similar  conclusion  was 
made  by  Ellis  (1937),  who  reported  that  if 
mussels  failed  to  respond  by  shell  closure  to  low 

dissolved  oxygen,  then  they  were  more  vulnerable 
to  destruction  by  pollution.  Extended  gaping  of 
the  valves  usually  precluded  death.  In  the 
laboratory  tolerance  tests  when  a  mussel  began 
to  gap  its  valves,  death  would  usually  follow 
within  several  hours. 

Mussels  that  were  stressed  usually  siphoned 
less  and  had  their  valves  closed  for  longer  periods 
than  the  non-stressed  specimens.  Badman  (1975) 
noted  that  under  hypoxic  conditions,  Elliptio 
dilatatus  and  Pleurobema  cocdneum  increased 
periods  of  valve  closure  and  reduced  filtration 
rates,  whereas  in  contrast,  Allen  (1923)  reported 
widening  of  the  siphons  and  mantles  to  pass  more 
water  through  the  mussel  (increased  respiration) 

Table  8.   Percentage  survival  to  diluted  sewage  in  the  Blanco  River  side  channel. 

Species  (Number  Used) 

7  days      14  days 

21  days 

28  days 

Amblema  p.  plicata 



Anodonta  imbecillis        (10) 



Corbicula  manilensis       (20) 





Cyrtonaias  tampicoensis    (11) 




October  30, 1979 

Vol.94  (4) 

Table  9.   Substrate  composition  of  two  typical  collecting  areas. 


U.S.  Series  No. 

Size  (mm) 














Coarse  gravel 





Medium  gravel 





Fine  gravel 





Very  coarse  sand 





Coarse  sand 





Medium  sand 





Fine  sand 





as  a  result  of  low  oxygen  levels.  The  various 
species  may  respond  differently  to  environmental 

The  mussels  most  tolerant  of  low  dissolved  ox- 
ygen were  collected  from  standing  or  slow  mov- 
ing waters.  For  example,  the  more  tolerant 
Anndonta  imbecillvi  and  Toxolasma  texasensw 
were  taken  from  ponds  or  reservoirs,  while  the 
more  sensitive  Amblema  p.  piicata  was  collected 
in  the  fast  moving  waters  of  the  Blanco  River.  At 
least  for  some  mussels,  tolerance  to  low  dissolved 
oxygen  levels  might  be  correlated  with  distribu- 

Insufficient  dissolved  oxygen  was  suggested  by 
Isom  (1971)  as  a  cause  for  the  decline  of  the 
endemic  mussel  fauna  in  Fort  Loudoun  Reser- 
voir, Tennessee.  Organic  enrichment  of  the  reser- 
voir was  apparently  the  causative  agent. 

Perhaps  even  the  rapid  colonization  of  aquatic 
habitats  by  Corhkula  manilensis  is  due  to  their 
tolerance  to  stressful  physicochemical  conditions 
as  well  as  their  reproductive  capabilities.  Hable 
(1970)  found  that  Corhkula  was  resistant  to  low 
oxygen  levels  and  that  the  presence  of  Anodonta 
imheciltia  and  Corhicula  manilensi.'i  in  Fort  Lou- 
doun    Reservoir,    when     they    had     not    been 

previously  detected  in  the  Tennessee  River,  may 
have  been  -due  not  only  to  their  fecundity,  but 
also  to  their  relative  high  tolerance  to  low 
dissolved  oxygen.  As  with  Corbicida  maniletisis, 
Anodonta  imbedllis  is  monoecious  and  has 
glochidia  that  may  develop  to  maturity  without  a 
living  host  (Murray  and  Leonard  1962). 

The  lack  of  significant  differences  in  survival 
capacities  to  elevated  ammonia  levels 
demonstrated  that  of  the  mussels  tested,  all  are 
relatively  sensitive  to  ammonia.  In  aerated 
aquaria,  where  the  pH  of  the  testing  waters 
varied  from  7.8  to  8.2  and  was  similar  to  the  pH 
of  the  Blanco  River,  concentrations  of  5  mg 
ammonia-N  1'  were  lethal  to  40%  of  the 
mussels  tested  in  seven  days  (Table  6).  The  am- 
monium ion  (NH,)  is  not  very  toxic,  but  molec- 
ular NHj  is  highly  toxic.  The  proportion  of 
ammonia  to  ammonium  ions  greatly  increases 
with  decreasing  hydrogen  ion  concentrations,  and 
as  reported  by  Ellis  (1937),  pH  is  an  important 
factor  in  the  toxicity  of  ammonium  compounds  to 
aquatic  animals.  For  instance,  Ellis  (1937)  found 
that  for  daphnia  and  gammarids,  the  toxicity  of 
ammonium  compounds  increased  200%  or  more 
as  pH  increased  from  7.4  to  8.0. 

Vol.  94  (4) 

October  30. 1979 


With  concentrations  of  6.8  mg  ammonia-N  1' 
(pH  7.85),  the  diluted  sewage  in  the  side  channel 
contained  ammonium  levels  which  exceeded  the 
experimental  ammonium  levels  utilized  in  the 
laboratory.  The  concentrations  of  18.4  mg 
ammonia-N  1"'  in  the  sewage  effluent  would  pre- 
sent potentially  lethal  levels  if  the  effluent  com- 
posed 20%  or  more  of  the  total  stream  flow.  Such 
conditions  would  exist  in  the  Blanco  River  if  the 
flow  was  reduced  to  about  0.1  m^  sec"'  which 
would  be  15  times  lower  than  the  minimum  flow 
(1.5m '  sec-')  found  for  1976-1977. 

Over  long  periods,  much  lower  concentrations 
of  ammonia  may  be  detrimental  to  mussels.  Ellis 
(1937)  found  that  1.5  mg  ammonia  1'  was  the 
maximal  concentration  not  indicative  of  organic 
pollution.  In  streams  mth  pH  values  ranging 
from  7.4  to  8.5,  ammonia  levels  of  2.5  mg  1' 
would  tend  to  be  detrimental  to  many  freshwater 
animals  (Ellis  1937).  Levels  of  ammonia-N  prob- 
ably should  be  kept  below  1  ppm  in  all  streams 
containing  mussel  populations. 

Mussels  are  more  sensitive  to  ammonia  than 
the  common  goldfish,  Carassiiis  auratus.  which 
Ellis  (1937)  listed  as  tolerant  to  10  ppm  am- 
monium carbonate  (pH  7.7)  for  more  than  four 
days.    Conversely,    and    as    mentioned    earlier, 

physiologically  mussels  are  less  sensitive  to  low 
dissolved  oxygen  levels  than  goldfish.  However,  a 
mussel's  chances  for  survival  when  unfavorable 
conditions  occur  is  reduced  by  their  lack  of 
mobility  and  confinement  to  the  substratum. 
Ma.ximum  allowable  ammonia-N  levels  in  a 
fishery  is  0.02  mg  l"'  (Wellingham,  1973;  NAS 
and  NAE,  1972). 

In  general,  laboratory  tolerance  tests 
demonstrated  that  Corbicula  manilensis  was  the 
least,  and  Amblema  p.  plicata  the  most  sensitive 
of  the  mussels  (Table  5).  However,  not  all 
Amblema  can  be  called  "sensitive".  On  the  basis 
of  their  high  densities  in  "conditionally  polluted 
areas",  Richardson  (1928)  postulated  a  species  of 
Amblema  (A.  mtiplicata)  to  be  the  least  sensitive 
of  the  mussels  sampled  in  the  Illinois  River. 

Since  specimens  for  this  study  were  collected 
by  handpicking,  the  youngest  age  classes  of 
mussels  were  not  observed.  Mussels  less  than 
three  years  of  age  are  commonly  overlooked  when 
handpicking  (Van  Cleave  1940).  No  information, 
therefore,  was  collected  on  mussel  reproduction 
when  exposed  to  the  stressors  or  on  larval 
tolerances.  It  is  likely  that  individuals  of  the 
same  species,  but  of  different  ages,  have 
dissimilar  tolerances  to  stream  pollutants  (Ellis 

Table  10.   Quantitative  samples  of  the  freshwater  mussels  of  the  Blanco  River. 


Upstream  (ic/m^) 

Site  1       Site  2 

Site  3 

Downstream  (x/m2) 

Site  5        Site  6 

Amblema  p. 




















Lamps  ills  a. 






Lamps ills 













October  30. 1979 

Vol.94  (4) 

1937).  Pollution  tolerance  data,  therefore,  must  be 
viewed  with  caution. 

Based  upon  the  results  of  this  study  the  sug- 
gestion by  Weber  (1970)  that  Corbicnla  is  less 
tolerant  than  Anodonta  imbecillis  to  organic 
pollution  may  be  incorrect. 

Due  to  the  intolerance  of  mussels  to  diluted 
sewage  in  the  side  channel  and  because  the 
substrate  and  other  physical  factors  below  the  ef- 
fluent of  the  treatment  plant  of  San  Marcos  are 
basically  similar  to  those  factors  upstream,  the 
decreased  number  of  mussels  downstream  was 
probably  due  to  organic  enrichment  (Fig.  10).  The 
severity  of  sewage  pollution  would  increase 
tremendously  during  low  or  no  flow  periods.  No 
other  explanation  is  available  at  present  to  ac- 
count for  the  disproportionate  lack  of  mussels 
below  the  entrance  of  the  sewage  effluent  in  the 
Blanco  River. 

Simons  and  Reed  (1975)  noted  that  the 
molluscan  segment  (mostly  mussels)  of  the  ben- 
thic  community  represented  a  more  sensitive  por- 
tion of  the  macrobenthos  than  did  most  insects  in 
the  North  Anna  River,  Virginia.  The  point  of  full 
"biological  recovery"  of  the  North  Anna  River 
was  assumed  to  have  been  where  the  mussel 
populations  had  been  reestablished  (Simons  and 
Reed  1975). 

As  suggested  by  Ingram  (1957)  and  from  data 
presented  here,  mussels  may  have  value  as  in- 
dicators of  nonpolluted  waters  because  their 
presence  typically  indicates  high  dissolved  oxygen 
and  associated  chemical  and  physical  conditions. 
For  determination  of  the  severity  of  water  pollu- 
tion reduced  numbers  of  "clean  water"  species 
which  were  formerly  present  in  the  stream  may 
be  more  important  than  an  abundance  of  known 
pollution  resistant  forms  (Richardson  1928). 

The  following  concluding  remarks  can  be  made 
from  the  tolerance  tests  and  field  studies. 

(1)  Low  dissolved  oxygen  levels  (0  -  0.5  mg  Oj 
1')  proved  lethal  to  47%  of  the  mussels  tested  in 
seven  days. 

(2)  Levels  of  5  mg  NHVNHj  1"'  (pH  7.S  to 
8.0  were  lethal  to  40%  of  the  mussels  tested  in 
seven  days. 

(3)  Even  in  waters  with  dissolved  oxygen  levels 
not  indicative  of  pollution,  ammonia  levels  can  be 
lethal  to  mussels. 

(4)  Corbicula    manilensis    is    generally    more 

tolerant  and  Amblema  p.  pHcata  less  tolerant 
than  the  other  mussels  tested  to  stressors 
associated  with  sewage  enrichment. 

(5)  Even  though  the  physicochemical 
parameters  did  not  indicate  stressful  conditions 
on  the  days  sampled,  mussels  of  the  Blanco  River 
seemed  to  have  been  adversely  affected  by  enrich- 
ment from  the  secondary  sewage  treatment  plant 
of  San  Marcos.  Fewer  mussels  were  found 
downstream  from  the  sewage  plant  than 


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Hannan.  H.  H..  W.  C.  Young,  J.  J.  Mayhew.  1973.  Nitrogen 
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Miguel  A.  Klappenbach 

Museo  Nacional  de  Historia  Natural 
Montevideo,  Uruguay 

Marginella  corderoi  was  described  and  il- 
lustrated by  Carcelles  (1953:10,  pi.  III.  fig.  17,  18) 
as  coming  from  places  located  in  the  South 
American  Atlantic  littoral,  at  the  mouth  of  the 
Rio  de  la  Plata.  The  description  as  well  as  the  il- 
lustrations, left  us  with  a  certain  doubt  about  the 

correct  allocation   of  the   species   in   the  genus 

Subsequently  we  examined  the  holotype 
(M.A.C.N.  "Bernardino  Rivadavia"  N°  24194) 
coming  to  the  conclusion  that  what  we  really  had 
was  a  Volutidae,  without  being  able,  though,  to 


October  30. 1979 

Vol.94  (4) 

determine  the  genus  for  lack  of  knowledge  of  the 
soft  parts.  Rios  (1970:112)  also  expressed  his 
doubts  about  it,  placing  the  generic  name  in 
quotation  marks  and  stating  that  it  did  not  look 
like  A  Marginella. 

Recently  we  have  obtained  on  the  shore  of  the 
Brasilian  State  of  Rio  Grande  Do  Sul  (a3°17'S 
-.50°34'W  Operation  CEDIP  II,  10-20-72,  in  a  thin 
muddy  bottom)  some  specimens  of  the  above  men- 
tioned species  with  its  soft  parts  (Col.  Male. 
M.N.H.N.  N°  8809).  We  then  prepared  the  radula 
and  verified  that  the  species  belonged  to  the  sub- 
family Odontocymbiolinae  (Clench  &  Turner,  1964: 
170).  The  radula  is  formed  by  a  single  row  of 
rachidian  teeth  and  each  one  of  them  is  made 
up  of  a  basal  plate  forming  a  medium  angle  (Fig. 
2)  from  which  a  long,  narrow,  curved,  hook- 
shaped  tricuspid  emerges.  This  characteristic,  the 
large  protoconch  and  the  proportionally  short 
spire,  allow  us  to  place  this  species  close  to  Odan- 
tocymbiola  Clench  &  Turner,  1964. 

Nevertheless,  the  details  of  the  sculpture,  axial- 
ly  ribbed,  crossed  by  thinner  spiral  cords  clearly 
separate  it  from  this  genus.  However,  this 
sculpture  is  a  characteristic  of  Miomelon  philip- 
piana  (Dall,  1890)  type-species  of  the  genus 
Miomelon  (Dall,  1907:365).  But  the  latter  presents 
a  high  spire  and  very  small  protoconch  with  a 
rachidian  tooth  formed  by  a  basal  plate,  roughly 
rectangular,  and  no  angle  in  the  middle  portion 
(Pilsbry  &  Olsson  1954:pl.  27,  fig.  10)  (Stuardo  & 

FIG.  1.  Minicymbiola  (new  genus)  corderoi  (Carcelles.  lH.'i.l). 
Tj/pe  <if  Ihe  genii.s.  PiimtiflM'  specimen  No.  ■U9J,,  Malaciilayical 
Collection,  Museo  Nacional  de  Hiitoria  Natural .  Montevideo. 
200km  west  of  Urug-uay  in  loometers. 

Villarroel,  1974:14.5,  fig.  17);  these  features  do  not 
agree  with  the  species  of  Carcelles. 

For  the  above  reasons,  we  think  that  it  would 
be  convenient  to  establish  a  new  genus  for  the 
species  with  the  following  diagnosis: 

Minicymbiola  gen.  nnv. 

Type-Species:  Manjinelln  corderoi  Carcelles, 

Dicujiiosis:  Shell  small  within  the  subfamily. 
The  largest  specimen  we  know  is  28  mm  in  length 
(N°  11.430  of  the  Collection  Museo  Oceanografico 
de  Rio  Grande,  Brazil)  and  it  was  obtained  in 
Uruguayan  waters  3.5°05'S  and  52°40'W,  117  m 
in  depth.  Spire  short;  protoconch  moderately  large 
and  dome-shaped.  Axial  sculpture  formed  by 
rounded  ribs  crossed  by  thinner  spiral  cords. 
Radula  with  arched  basal  plate  forming  an  angle 
at  its  middle  part  and  bearing  three  long,  narrow 
and  curved  cusps.  Periostracum  and  operculum 
are  absent. 

Distribution:  At  present,  represented  only  by 
the  type-species  which  is  found  in  the  South 
American  Atlantic  from  the  State  of  Parana, 
Brazil,  in  the  North.  (Rios,  1970:112)  to  the  Pro- 
vincia  of  Buenos  Aires,  Republica  Argentina,  in 
the  South. 

Remarks:  The  subfamily  Odontocymbiolinae, 
Clench  &  Turner,  1964,  contains  five  genera:  Odon- 
tocymbiola  Clench  &  Turner,  1964;  Miomelon 
Dail,  1907;  Tractolira  Dall,  1896;  Volutoconm 
Crosse.  1871;  and  now  Minicifmbivla.  The  only 
known  living  species  of  Tractolira  are  from 
Pacific  waters,  off  Central  America,  in  abyssal 
depths.  The  protoconch  forms  an  apical  spur 
that  characterizes  them  easily. 

Vdlutoconiis  has  four  species  restricted  to 
Australian  watei-s.  In  this  genus  the  protoconch 
bears  an  apical  spur,  and  other  features  are  pre- 
sent that  allow  us  to  separate  it  from  the  genera 
known  to  South  American  waters  (Atlantic  or 
Pacific).  A  second  species,  represented  only  by 
the  holotype  up  to  now.  from  a  locality  between 
the  Malvinas  Islands  and  Magailanes,  Miomelon 
ticoresbyana  Powell,  1951,  possibly  should  be 
removed  from  this  genus  when  its  radula  is 
known  and  placed  in  Minici/mbiola.  Its  short 
spire,  stump-shaped  apex,  and  its  sculpture  con- 
sisting of  very  weak  axial  lines  of  growth 
(Weaver  &  du  Pont,  1970:  pi.  .56,  E.F.)  similar  to 

Vol.94  (4) 

October  30, 1979 


the  ones  found  in  Odontoritmhiola  pescalia  Clench 
&  Turner,  1964,  or  in  young  specimens  of  Odon- 
tocymhiola  magellanica  (Gmelin,  1791)  indicate 
its  affinity  with  Odontoci/mbiola  and  separate  it 
from  Mianielon. 

Finally,  we  have  the  genus  Odontoci/mbinla 
Clench  &  Turner,  1964,  which  contains  four 
species  living  in  South  American  Atlantic  waters: 
0.  ainericuna  (Reeve,  1856),  0.  mmiclUtnicn 
(Gmelin,  1791),  0.  pescalia  Clench  &  Turner,  1964 
and  0.  sHb)i()d()>in  (Leach,  1814):  the  last  one  was 
included  in  the  genus  recently  by  Weaver  &  du 
Pont  (1970:130)  and  by  Castellanos  (1970:2).  The 
last  three  species  present  a  characteristic  unit 
that  gives  homogeneity  to  the  gi"oup.  This  is  not 
the  case  with  0.  americana  (Reeve,  1856)  also 
considered  to  be  in  the  genus:  but  its  smaller 
size,  smooth  e.xterior  surface  and  rather  sharp 
nodes  separate  it  from  the  former  ones.  We 
should  emphasize  that  Clench  &  Turner  (1964: 
129)  stated  that  the  characteristics  of  the  shell  of 
0.  americana  (Reeve,  1856)  are  closest  to  the  ones 
of  AulJcirm  vespertilio  (Linn^,  17.58)  from  the 
West  Pacific,  but  the  radulae  are  different,  plac- 
ing the  species  in  different  subfamilies. 

In  short,  it  appears  to  be  logical  to  include  the 
new  genus  Minicymbiola  in  the  subfamily  Odon- 
tocymbiolinae  based  on  the  radular  char- 
acteristics. Also  it  appears  as  a  very  distinct 
genus  easily  separated  from  Odontocifm^iola  by 
its  small  size  and  conspicuous  a.xial  sculpture  and 
its  spire.  It  is  easily  distinguished  from  Miomdan 
by  its  short  spire,  large  and  stump-shaped  apex 
and  by  the  conformation  of  the  basal  plate  of  the 
rachidian  tooth. 

The  name  Minicymbiola  cnrderni  (Carcelles, 
1953)  should  not  be  confused  with  another  volute, 
Ffovocator  corderoi  Carcelles,  1947,  an  entirely 
different  species. 

FIG.  2.  Twd  rachidian  radulae  of  Minicymbiola  corderoi 
(Carcelles.  195S).  from  a  specimen  off  Rio  Grande  Do  Sul. 


Castellanos.  A.  A.  de.  1970.  Reubicaci(5'n  de  algunas  especies  de 

Volutidae  del   Mar  Argentine,  Neotropica,   16(49):  1-4,  La 

Plata.  Argentina. 
Carcelles.  A.  19.5.3.  Nuevas  especies  de  Gastropodos  Marines  de 

las  Republicas  Oriental  del   Uruguay  y  Argentina.  Com. 

Zool.  Mus.  Hist.  Nat.  Montevideo,  4(70):  1-16.  pis,  1-.5. 
Clench,    W.    J.    &    Turner,    R.    D.    1964.    The    Subfamilies 

Volutinae,  Zidoninae,  Odontocymbiolinae  and  Calliotectinae 

in    the    Western    Atlantic.    Johnsonia,    4(4.3):  129-180.    pis. 

Dall,   W.   H.   1907.   A   Review  of  the   American   Volutidae. 

Smith.  Misc.  Coll..  48:341-37.3. 
Pilsbry,  H.  A.  &  Olsson.  A.  A.  19.54.  Systems  of  the  Volutidae, 

Bull  Amer.  Paleont.  35(152):27.5-306.  pis.  25-28. 
Rios,  E.  C.  Coastal  Brazilian  Seashells,  1-255,  pis.  1-60.  4  maps. 

Rio  Grande.  Brazil. 
Stuardo.  .J.  &  Villarroel.  M.  1974.  On  Some  Living  and  Fossil 

Volutes  Referred  to  Miomelon  Dall.  1907  and  Proscaphella 

von  Ihering.  1907,  Tlie  Veliger.  17(2):139-1.5.5. 21  figs. 
Weaver,  C.  S.  &  du  Pont,  .J.  E.  1970.  The  Living  Volutes, 

Monograph  Ser.  1.  Delaware  Mus.  Nat.  Hist.  I-XV.  1-.375, 

pis.  1-79. 


October  3n.  1979 

Vol.  94  (4) 


Alex  S.  Tompa 

Museum  of  Z<)olop\- 

University  of  Michigan 

Ann  Arbor,  Michigan  48109 

As  the  embryo  of  Stenotrema  leal  (Binney)  undergoes  development,  it  first  dis- 
solves the  calcite  ai/stnls  in  the  mder  part  of  the  egg,  not  uniformly  throughout 
the  surface  of  the  egg,  but  at  a  local  area  of  the  shell.  Fiimlly  the  rest  of  the  egg 
shell  calcium  crystals  are  dissolved.  This  observation  is  at  odds  with  previous  ex- 
pl/ui(tti<i)is  of  egg  shell  dissolution  only  by  lowering  egg  albumen  pH.  Now  it  seems 
that  some  larval  organ  is  specifically  applied  against  the  egg  shell  and  causes  local 
calcium  resorption  in  one  area  at  a  time  The  two  mx>st  likely  organs  which  could 
be  involved  are  the  embryonic  podocyst,  which  is  a  modification  of  the  foot,  or  the 
mouth  region. 

Recent  work  has  clearly  demonstrated  that  the 
egg  shell  of  most  land  snails  contains  calcium 
carbonate  crystals  which  the  embryo  utilizes  for 
its  own  calcium  needs  during  development  (Tom- 
pa,  1975).  Almost  all  the  work  pertaining  to  such 
embryonic  calcium  utilization  has  involved  eggs 
which  are  said  to  be  heavily  calcified  (Tompa, 
1974),  i.  e.,  they  have  a  brittle,  hard  calcium  shell. 
In  such  a  system,  using  the  eggs  of  Strophocheilus 
oblongus,  it  has  been  shown  that  the  egg  fluid  pH 
dramatically  decreases  and  fluid  calcium  concen- 
tration concomitantly  increases  during  develop- 
ment (Tompa,  1979).  Because  of  this  documenta- 
tion, it  appeared  that  all  of  the  egg  shell  calcium 
must  be  dissolved  at  the  same  rate,  equally  all 
around  the  egg,  since  a  pH  decrease  in  the  egg 
albumen  fluid  would  cause  erosion  everywhere 
where  it  touches  the  egg  shell.  The  present  study 
deals  with  changes  associated  with  development 
in  the  partly  calcified  egg  of  the  land  snail 
Stenotrema  leai  (Binney)  (alias  monodon  (Rac- 
kett)).  This  study  suggests  that  a  pH  change  in 
the  egg  albumen  is  not  sufficient  by  itself  to  ex- 
plain the  differential  disappearance  of  calcite 
crystals  in  the  outer  egg  layers  in  partly  calcified 


Stenotrema  leai  snails  were  collected  within 
the  city  limits  of  Ann  Arbor,  Michigan.  They 
were  brought  into  the  laboratory,  fed  on  a  diet  of 
carrots,  chalk  and  filter  paper,  and  were  found  to 
mate   and   breed   successfully.   Containers   were 

checked  for  eggs  every  day;  when  found,  they 
were  immediately  isolated  and  placed  inside  a 
small  glass  Petri  dish  containing  ash-free  filter 
paper  moistened  with  deionized  water.  Qose-up 
photographs  were  periodically  made  of  the 
developing  eggs. 


A  total  of  ten  clutches  were  examined.  The 
number  of  eggs  per  clutch  was  2.06  ±  1.06,  with 
each  clutch  ranging  in  size  from  1-4  eggs.  The 
average  size  of  the  eggs  laid  was  2.28  ±  0.14  X 
2.29  ±  .18  mm.  Approximate  time  of  hatching  at 
20°C  was  two  weeks.  The  pictures  illustrated  in 
Figure  1  were  taken  from  eggs  of  the  same 
clutch,  in  increasing  order  of  age,  so  that  Figure 
1  is  a  newly  deposited  egg,  while  Figure  4  is 
within  a  few  days  of  hatching. 

The  most  striking  aspect  of  this  developmental 
sequence  is  that  the  egg  crystals  are  not  dissolved 
uniformly  around  the  embryo.  Instead,  certain 
areas  of  the  shell  are  preferentially  dissolved, 
often  completely,  before  other  parts  of  the  calcite 
layer  were  involved.  Figure  2  is  an  especially 
striking  example  of  this  phenomenon,  where  one 
small  area  of  the  egg  shell  has  been  completely 
denuded  of  calcite  crystals  while  the  rest  seem 
intact.  As  indicated  in  Figure  4,  most  eggs  lose 
their  opacity  by  the  time  of  hatching,  and  become 
transparent  from  loss  of  the  crystal  layers  in  the 
outer  egg  shell.  This  same  type  of  localized  calcite 
dissolution  has  been  subsequently  observed  with 

Vol.94  (4) 

October  30. 1979 





FIGS.  1-4  Illustrate  the  appearance  of  prugresmvely  older  eggs 
of  Stenotrema  leai  during  incubation  at  room  temperature. 
1,  is  a  freshly  deposited  egg:  2,  is  older  by  several  days  and 
shows  a  single  prnnounced  area  of  crystal  dissolution:  3,  is 
older  still,  with  a  more  extensive  area  of  calcium,  carbonate 
erosion.  4,  is  an  egg  only  a  few  days  from  the  time  of 
hatching:  here  the  embryo  occupies  most  of  the  egg  and  only 
a  very  snudl  amount  of  caleite  crystal  material  is  left.  This. 
too,  will  disappear  before  final  hatching.  White  scale  bar  in 
the  upper  right  comer  indicates  0.5  mm.  All  four  eggs  are 
from  the  same  clutch:  i  is  the  maximum  number  of  eggs 
found  per  chdch  for  this  species  in  the  laboratory. 

eggs  of  other  partly  calcified  eggs,  such  as  those 
of  the  pulmonates,  Varohadra  yeppoonensis  from 
Australia  and  Helicodiscus  parallelus  from  the 
northern  United  States. 

act  site  of  caleite  disappearance.  Especially   in 
the   earlier   parts   of  development,   the   egg    is 
opaque  and  the  embryo  is  not  visible.  Presently, 
the  best  guess  is  that  either  1)  the  embryonic  foot 
organ  called  the  podocyst  (see  Gather  and  Tompa, 
1972)  is  applied  to  this  area  to  dissolve  calcium 
carbonate,  or  that  2)  the  mouth  and  its  secretions 
are    directly    responsible.    We    know    that    im- 
mediately  post-hatching,   the  neonate  consumes 
all  of  the  egg  shell  remnants  available  and  may 
even   rasp  on  the  shells  of  other   nearby  eggs 
(numerous   sources;    personal   observations   with 
such   snails   as   Helix,   Stenotrema,   Anguispira, 
etc.).  On  the  other  hand,  it  is  also  known  that  the 
podocyst,  an  embryonic  organ  modified  from  the 
foot,  functions  in  taking  up  egg  albumen  (Gather 
and   Tompa,   1972)  and   indeed   it  may  have  a 
calcium  resorbing  function  as  well,  such  as  in  the 
avian   embryo's  chorioallantois  (Terepka  et  ai, 
1969).    This    is   all    the    more   likely    since   the 
podocyst  is  often  seen  directly  appressed  to  the 
inner  egg  shell  surface  for  long  periods  of  time. 
The  podocyst  is  often  so  large  in  later  develop- 
ment that  it  makes  direct  contact  with  50%  or 
more  of  the  inner  surface  area  of  the  egg  shell. 
Therefore,    either    the    podocyst    or    the    larval 
mouth  area  takes  part  in  egg  shell  caleite  resorp- 
tion. The  embryo,  of  course,  needs  this  calcium  to 
build  its  first  whorls  of  the  body  shell,  the  pro- 
toconch,  so  that  it  has  a  hard  shell  by  the  time  of 
hatching  (Tompa,  1975).  No  doubt,  such  a  hard 
shell,  into  which  the  neonate  can  withdraw,  has  a 
direct  and  immediate  selective  advantage  where 
micropredators  abound;  the  calcific  egg  shell  is 
dissolved,  then  re-precipitated  by  the  embryo  as 
aragonite  body  shell  crystals. 


The  cause  of  such  specific  and  localized  caleite 
dissolution  is  not  clear  and  conflicts  with  the 
previously  held  ideas  that  a  general  erosion  of 
the  egg  shell  crystals  occurs  during  development. 
The  present  study  suggests  that  while  there  may 
be  a  moderate  degree  of  general  crystal  dissolu- 
tion during  development,  limited  areas  are 
preferentially  attacked  and  rapidly  dissolved. 

It  has  not  been  possible  to  associate  the  jux- 
taposition of  any  embryonic  organ  with  the  ex- 


Gather.  J.  and  A.  Tompa  1972.  The  podocy-st  in  pulmonale 
evolution.  jV/a/ar.  Rev.  5:1-3. 

Terepka.  A.,  M.  Stewart  and  N.  Merkel  1969.  Transport  func- 
tions of  the  chick  chorioallantoic  membrane.  II.  Active 
calcium  transport,  in  vitro.  Expt.  Cell  Res.  58:107-117. 

Tompa.  A.  1974.  The  structure  of  calcareous  snail  eggs.  Malac. 
flpr.  7:49-50. 

197.5.  Embryonic  use  of  egg  shell  calcium  in  a 

gastropod.  Nature  255:232-33. 

1979.  pH  and  calcium  concentration  changes  in  a 

molluscan  egg  during  development.  Experientia.  35:812-813. 

138  THE  NAUTILUS  October 30. 1979  Vol.94  (1) 


Arthur  H.  Clarke 

Smithsonian  Institution 
Washington.  D.C.  20560 


Field  data  associated  with  the  91  species  and  subspecies  of  boreal  and  arctic 
North  American  freshwater  gastropods  were  analyzed.  Most  species  and  subspecies 
are  eurytopic,  but  a  few  are  entirely,  or  nearly,  restricted  to  lakes  of  particular 
trophic  levels.  These  are:  Valvata  sincera  sincera  Say  for  oligotrophic  lakes. 
Fossaria  decampi  fStreng)  and  Stagnicola  catascopium  (Say)  for  oligotrophic  and 
mesotrophic  lakes,  and  Amnicola  limosa  (Say).  L\Tnnaea  stagnalis  juguiaris  (Say), 
and  Planurbula  armigera  (Say)  for  eutrophic  lakes.  Physa  integra  Haldeman  is  fre- 
quently associated  unth  mesotrophic  lakes  but  also  occurs  in  other  habitats.  The 
indicator  species  are  illustrated  and  briefly  described. 

The  literature  dealing  with  gastropods  as  in- 
dicators of  water  quality,  especially  in  regard  to 
water  pollution,  has  been  recently  reviewed  by 
Hannan  (1974).  That  paper  includes  a  survey  of 
existing  knowledge  (including  new  observations) 
about  the  tolerances  of  many  species  of 
gastropods  to  extremes  of  pH,  alkalinity,  total 
CO2.  dissolved  O2,  and  temperature,  and  to  in- 
dustrial wastes  and  pesticides.  The  fundamental 
value  of  this  approach  is  unquestioned,  although 
as  that  author  has  also  pointed  out,  most 
moUusks  have  broad  tolerances  for  environmental 
perturbations  and  "almost  every  common  species 
has  been  found  in  polluted  environments"  (loc  cit. 
p.  302.) 

The  present  study  seeks  to  assess  the  possible 
utility  of  freshwater  gastropods,  not  as  pollution 
indicators,  but  as  indicators  of  progressive 
ti'ophic  lake  stages.  It  is  based  on  the  literature 
and  on  about  2000  freshwater  field  collections 
and  associated  observations  made  since  1950 
throughout  cool-temperate,  boreal,  and  arctic 
North  America  (Clarke,  1973.  1980).  Although  the 
field  experience  has  been  fairly  extensive,  in  most 
instances  the  trophic  character  of  a  lake  was 
judged  solely  on  qualitative  observations.  The 
conclusions  presented  here  must  therefore  be  con- 
sidered provisional.  Most  freshwater  species  listed 
here  are  eurytopic  or  wide-ranging  in  habitat 
tolerance,  but  others  are  restricted  to  lakes  in 
various  stages  of  development. 

Of  course  mollusks  have  biological  require- 
ments which  affect  their  utility  as  indicator 
organisms.  Since  most  pulmonates  are  ranfined  to 

shallow  water  where  access  to  the  atmosphere  is 
possible,  they  commonly  occur  near  the  water 
line  or  among  emergent  vegetation.  Many, 
however,  are  apparently  able  to  capture  and  use 
the  oxygen  released  by  plants  during  photosyn- 
thesis and  in  some  the  pulmonary  cavity  is  filled 
with  water  and  functions  as  a  branchium  or  gill. 
Such  adapted  pulmonates,  like  prosobranchs.  can 
thrive  in  the  deep  profundal  zone  of  lakes. 
Although  some  species  have  been  found  in  water 
with  very  low  oxygen  saturation  levels  (Harman. 
1974),  it  is  unlikely  that  any  species  is  able  to 
live  for  long  periods  in  regions  which  periodically 
undergo  prolonged  and  dra.stic  reductions  in 
dissolved  oxygen,  such  as  within  the  hypolimnia 
of  many  eutrophic  lakes.  Eggs  of  gastropods,  in 
fact,  ai'e  even  more  susceptible  to  low  oxygen 

Table  1  represents  a  preliminary'  attempt  to 
tabulate  the  relative  abundance,  regional  geo- 
graphical distribution,  and  kinds  of  water  bodies 
inhabited  by  the  freshwater  gastropods  of 
northern  North  America.  The  species  list  is 
thought  to  be  complete  for  Canada  and  virtually 
so  for  Alaska.  Nearly  all  of  the  species  found  in 
New  England  and  the  states  bordering  Canada 
are  also  included,  and  some  can  serve  as  laketype 

The  attributes  which  a  species  should  possess 
to  be  useful  as  an  indicator  of  lake-stages  are: 
wide  geographical  distribution,  comparative 
abundance,  relative  stenotopy,  and  ease  of  iden- 
tification. The  table  demonstrates  that  only  a  few 
of  the  91  species  and  subspecies  listed  combine  all 

Vol.94  (4) 

October  30, 1979 


Relative  Abundance,  Approxlnace  Distributions,  and  Uaual    ^j 
HablcaCB  □(  Che  Freshwacer  Gaattopoda  of  northern  North  Aseclca 

Lynnaea  atkaeoals  Dall 
Valvata  sincera  slncera 

Valvata  perdeprcsaa  Walker 

Foaaarla  decaapl  (Streng) 

Stagnlcola  caataacoplua 
catascopluB  (Say) 

SCagDlcola  keonlcottl  Bakei 

Phyaa  pioplnqua  Tryon 

Phyaa  Jennesal  Jenneaal 


Physa  hecerostcopha  (Say) 

Somatogyrus  subglobosus 

Phyaa  Integra  Kaldeman 

Clnclonacla  Cincinnati ens I 

Physa  gyrina  latchfocdl 

Hellsona  corpulentun 
verallionense  Baker 

Valvata  placlnalla  (Wilier) 

GonlabBBis  llvescens 

Llthoglyphua  vlreos  (Lea) 

BullBus  teotaculatus  (L) 

Foasaria  exigua  (Lea) 

Physa  Jennesst  atheaml 

Physa  coluablana  Henphlll 
Physa  lordl  Balrd 

lellsooa  campanulatuit 

caatpanuLatun  (Say) 

Stagnlcols  elodea  (Say) 
Stagnicola  proslaa  (Lea) 
Valvata  slncera  ontarlenal 

Paeudosucclnla  colunella 

Bullmea  aegasotsa  (Say) 

Lymaca  scagnalls  Jugularts 

Stagnicola  arctlca  (Lea) 
(^raulua  deflectus  (Say) 

Hcllaoaa  trlvolvla  trlvolvl 

H  of  55'  IE  o!  9M' 







:  A  T  B  »  P 





I'hy.o  gyrina  gyrlna  Say 
CytauLus  parvus  (Say) 

I  Rafli 

Juga  pllclfera  (Lea) 

Canpetoma  declsuB  (Say) 

Vtvlparus  georglanus  (Lea) 

Clpongopaludlna  chlnensls 

Harstonla  decepca  (Baker) 

Lyogyrus  granun  (Say) 

Anilcola  walkert  Pllsbry 

Amlcola  llaosa  (Say) 

Foasaria  truncatula 


Radix  aurlculsrla  (L) 
Radix  peregra  (Wller) 
Acella  haldemanl    (Blnney) 

Armlger   crista   <L) 

KeneCus   Cooper 1   Baker 
Plsnorbula  amlgera    (Say) 
LaoDia   Crlvolvia   bioneyl 

Phyaa  concolor  Haldeoan 
Physa  hordacea  Lea 
Phyaa  nutcalll   Lea 
Laevapez  fuacus   (Adams) 
FerrlsBla  fragllls   (Tryoo) 
Fossarla  madlcells   (Say) 
naea  bulltaoldes 

BakerllynmMa  dalll    (Sakfr) 
Stagnicola   reflexa   (Say) 

Gyraulls  vennlcularls 


W  of  95*   E  of  9i'  OLICOTR  KESOTR  EUTROPH   VERHAJ, 

Fronenetus  tnbll 

( Cockerel 1) 


Physa  Jennesal  sklnoeri 


Apleia  hypnoruB 


Planorbula  caope 



T  B  H  P 
T  B  H  P 

Stagnicola  caperata  (Say) 

Stagnicola  aoatancDals 


Phyaa  Johnaoni  Clench 
Ferrlaala  rivularla   (Sav) 
Lonx  nuttalli   (Haldeman) 
Fomatlopsls   lapldarla   (Say) 
Fossarla   parva    (Lea) 

T  B  C 
T  B  C 











id    springs 
streams   and   sp  -Ings 

ant  hlbioi 
aa{  hlbloi 


Abbreviations.     Abumlance:  C,  abundant  or  cccraon:  R,  uncommon  op  rar«:  It  recently 
introduced  (relative  abundance  unstable).     Distribution:  A,  arctic;  T,  artic-bore*! 
transition  zooej  B,  boreal  forest;  H,  Mstem  mountain  regioni  P,  prairie  and  parkland 
region;  G,  Great  Lakes-St.  Lawrence  forest  region.     Habitat:  X,   frequent  occurreneej 
X,  infrequent  occurrence. 


a-tober  30, 1979 

Vol.91  (1) 



Bod\- whorl 


FIG.  1.  Part.'!  of  a  gastropod  ahell. 

of  these  attributes.  These  are:  (for  oligotrophic,  or 
early  stage,  lakes)'  Valvata  sincera  sincera  Say; 
(for  both  oligotrophic  and  mesotrophic  lakes) 
Fossaria  decampi  (Streng)  and  Stagnicola 
catascopium  (Say);  and  (for  eutrophic,  or  old,  ad- 
vanced stage,  lakes)  Amnicola  limosa  (Say),  Lipn- 
naea  stagnalis  jugularis  (Say),  and  Planorbula  ar- 
migera  (Say),  among  others.  In  southern  Canada 
Physa  Integra  Haldeman  occurs  most  frequently 
in  mesotrophic  lakes  and  is  therefore  of  some  use 
as  an  indicator  also,  but  it  is  not  entirely 
restricted  to  such  habitats.  It  is  also  worthwhile 
to  note  that  Stagnicola  caperata  (Say)  and 
Gyraulus  circumstriatus  (Tryon)  are  confined  to 
vernal,  or  temporary,  water  bodies  and  that 
Aplexa  hypnorum  also  ordinarily  occurs  only  in 
vernal  habitats. 

The  lake-stage  indicator  species  are  illustrated 
in  Fig.  2  and  briefly  described  below.  This  is  for 
the  benefit  of  those  who  are  not  familiar  with 
mollusks  but  who  wish  to  use  them  for  lake 
classification.  The  structural  features  mentioned 
are  illustrated  in  Figure  1.  However,  positive 
identification  can  only  be  achieved  by  considera- 
tion of  all  species  which  are  similar  to  the  in- 
dicator species.  For  additional  references  consult 
especially  Baker  (1928),  Clarke  (1973,  1980).  Har- 
man  &  Berg  (1971),  La  Rocque  (1966-70)  and 
Taylor  (1975). 


Valvata  sincera  sincera  Say  (Valvatidae)  (Fig. 
2,  A)  is  one  of  about  six  boreal  North  American 
species  and  subspecies  of  Valvata.  It  is  up  to  3.2 
mm  high  and  5  mm   wide,  with  four  rounded 

'  Lymnnra  nthaetifix.  although  known  only  from  oligotrophic 
lakes,  is  restricted  to  Alaska  and  extreme  northwestern 

whorls  sculptured  with  widely-spaced  coilabral 
threads  (8  or  fewer  per  mm),  and  a  round  oper- 
culum with  about  6  turns.  It  is  similar  to 
Valvata  .'iincera  helicoidm  Dall  but  that  sub- 
species is  more  northern,  is  larger  (up  to  7  mm 
wide)  and  has  finer,  more  crowded,  coilabral 
threads  (11  or  more  per  mm). 

Amnicola  limosa  (Say)  (Hydrobiidae)  (Fig.  2,  B) 
is  one  of  eight  boreal  North  American  species  in 
the  family.  Most  northern  hydrobiids  are  less 
than  6  mm  high,  are  higher  than  wide,  and 
possess  an  ovate  aperture  and  an  ear-shaped 
operculum  with  fewer  than  three  turns.  (One 
species,    Lyogyrus    granum,    has    a    round. 

FIG.  2.  Trophic  take-stage  indicator  .spprics  of  gaxtropixlx.  A, 
Valvata  sincera  sincera  (USNM,.  width  i.ll  mm/:  B, 
Amnicola  limosa  (USNM  2?109<).  height  J,.J  mm):  C,  Physa  In- 
tegra (NMC  J.i?J,.  height  ll.ti  mm):  D,  Fossaria  decampi 
(NMC  S97(ili.  height  11.2  mm):  E,  Lymnaea  stagnalis  jugularis 
(NMC  Ii7i9.  Iieight  61.1  mm):  F,  Stagnicola  catascopium 
catascopium  (NMC  2197.  height  1S.7  mm):  G,  J,  Planorbula 
armigera  (NMC  29S19.  mdth  6..i  mm):  H,  P.  armigera  show- 
ing position  of  internal  "teeth"  (NMC  ■i9:lJ,5.  width  J,.7  mm). 
.Abbreviations:  USNM.  Smith.tonian  In.ttitution:  NMC.  Na- 
t  iomil  Mu.<!eums  of  Canada. 

Vol.  94  (4) 

October  30, 1979 


multispiral  operculum).  A.  limnsa  is  up  to  4  1/2 
mm  high,  3  1/3  mm  wide,  with  4  1/2  convex 
whorls,  and  has  a  blunt  (but  not  truncated)  spire. 
It  is  often  abundant  on  lily  pads  and  other 
vegetation.  .4.  limom  occurs  throughout  the 
eastern  two-thirds  of  the  United  States  and 
Canada  south  of  the  tree-line. 


Fosmria  decarnpi  (Streng)  (Lymnaeidae)  (Plate 
1,  figure  D).  The  Lymnaeidae  is  a  large  family 
(26  Canadian  species  and  subspecies)  char- 
acterized by  shells  which  are  rather  thin,  high- 
spired,  and  dextral  (i.e.  coiled  clockwise  when 
viewed  from  above)  and  by  the  absence  of  an 
operculum.  Nearly  all  Fosmria  (6  species  in 
Canada)  are  less  than  12  mm  long  at  the  adult 
stage  (5-6  whorls)  and  most  are  less  than  8  mm. 
F  decarnpi  (normally  4-8  mm  long  and  about  half 
as  wide)  may  be  recognized  by  its  shouldered 
whorls,  laterally  flattened  body  whorl,  elevated 
and  reflected  inner  lip,  and  aperture  which  is 
narrowly  arched  above  and  broadly  rounded 
below.  It  occurs  in  the  Great  Lakes-St.  Lawrence 
drainage  and  north  and  west  throughout  the 
boreal  forest  region,  principally  in  large  lakes. 

Stagnicola  catascopium  catascopium  (Say) 
(Lymnaeidae)  (Plate  1.  figure  F).  Most  Stagnicola 
(10  species  and  subspecies  in  Canada)  are  medium- 
sized  (10-35  mm),  variable,  and  have  relatively 
strong  shells.  S.  catascopium  catascopimn  shows 
unusually  great  interpopulation  variability.  Most 
specimens  are  between  13  and  25  mm  long,  about 
2/3  as  wide,  with  a  rather  heavy  shell,  low  spire, 
broad  aperture,  inflated  whorls,  deep  suture,  and 
thickened  inner  lip.  It  occurs  across  North 
America  (except  in  northern  British  Columbia, 
Yukon  Territory,  and  Alaska)  south  to  about 
40°  north  latitude. 

Li/mnaea  stagnalis  jugularis  Say  (Lymnaeidae) 
(Plate  1,  figure  E)  (formerly  L.  stagnalis  appressa 
Say)  is  larger  (often  60  mm  long),  with  height 
about  double  the  width,  up  to  7  1/2  whorls,  and 
thin-shelled.  It  has  a  long,  narrow  spire  with  con- 
cave sides  and  flatly  rounded  whorls  and  a  bul- 
bous body  whorl.  This  common  subspecies  lives 
throughout  nearly  all  of  boreal  and  temperate 
Canada  and  the  northern  United  States  e.xcept 
for  the  extreme  eastern  portion,  i.e.  it  is  absent 

from  most  of  New  England,  the  Canadian  Mari- 
time Provinces,  and  noithern  Quelxx'. 

Phym  Integra  Haldeman  (Physidae)  (Plate  1, 
figure  C).  The  Physidae  (about  16  Canadian 
species  and  subspecies)  have  shells  which  are  thin 
in  most  species,  high-spired,  and  sinistral,  i.e. 
coiled  counterclockwise  when  viewed  from  above. 
They  all  lack  an  operculum  and  are  small  to 
medium-sized  (7-26  mm  high).  P.  integra  is  up 
about  15  mm  high,  9  mm  wide,  with  five  whorls, 
and  the  shell  is  thicker  and  heavier  than  that  of 
other  northern  species  of  Physa.  The  aperture  is 
thickened  within  by  a  white  ridge  and  many 
specimens  have  several  whiteish  collabral  bands 
representing  thickened  lips  formed  during 
previous  growth  stages. 

Planorbula  armigera  Say  (Planorbidae)  (Plate 
1,  figure  G-J).  The  Planorbidae  (about  21  Cana- 
dian species  and  subspecies)  have  shells  which  are 
nearly  all  flatly-coiled,  with  the  body  whorl  in 
about  the  same  plane  as  the  apex,  lack  an  oper- 
culum, and  may  be  small  to  quite  large  (3-32  mm 
in  shell  width).  P.  armigera  is  medium  sized 
(about  8  mm  wide,  3  mm  high,  5  whorls)  and  has 
one  (rarely  two)  set  of  5,  well-developed  "teeth" 
well  within  the  aperture  In  most  specimens  these 
teeth  may  be  seen  by  looking  into  the  aperture 
but  in  some  specimens  they  are  visible  only  by 
use  of  transmitted  light  (as  a  dark,  thickened 
area)  or  by  chipping  back  about  1/4  of  the  body 
whorl.  Only  one  other  northern  planorbid,  the 
larger  western  species  P.  campestiis  (Dawson), 
has  apertural  teeth  but  each  set  contains  6  teeth 
and  they  occur  only  in  juveniles.  P.  armigera 
lives  throughout  eastern  and  central  North 
America  from  Georgia  and  Louisiana  to  New 
Brunswick,  northern  Ontario,  and  the  vicinity  of 
Great  Slave  Lake  in  Canada's  Northwest  Ter- 

C.  0.  Berg  and  R.  S.  Houbrick  read  the 
manuscript  and  provided  u.seful  suggestions,  Ms. 
Cathy  Lamb  assisted  in  the  laboratory,  and  Ms. 
Valerie  Fulford  prepared  the  diagrammatic 
drawing.  The  photographs  were  provided  through 
the  courtesy  of  the  Smithsonian  Institution  and 
the  National  Museums  of  Canada.  I  am  grateful 
for  all  of  this  assistance. 


October  30, 1979 

Vol.  94  (4) 


Baker,  F.  C.  1928.  The  freshwater  Mollusca  of  Wisconsin.  Part 
1.  Gastropoda.  Wiscorusin  Academy  of  Science.  Arts,  and 
Ij-Aters.  pp.  i-.\x  +  1-.507,  plates  1-28. 

Clarke,  A.  H.  1973.  The  freshwater  molluscs  of  the  Canadian 
Interior  Btisin.  Malacotoyia  13:1-509. 

1980.  The  freshwater  MoUuscs  of  Canada  Na- 
tional Museums  of  Canada.  Ottawa  (in  press). 

Harman,  W.  N.  1974.  Snails  (Mollusca :Gastropoda)  m  C.  W. 
Hart.  Jr.  and  S.  L.  H.  Fuller  (Eds.).  Pollution  Ecology  of 
Freshwater  Invertebrates.  Academic  Press,  New  York,  N.Y., 
389  pages. 

Harman,  W.  N.  and  C.  0.  Bei^.  1971.  The  freshwater  snails  of 
Central  New  York.  Search  Agriculture.  Entomnlogy  (Ithaca) 
2.  Agricultural  E^xperiment  Station,  Cornell  University, 
Ithaca,  NY,  pp.  1-68. 

Taylor,  D.  W.  1975.  Index  and  bibliography  of  Lake  Cenozoic 
freshwater  Mollusca  of  Western  North  America.  Claude  W. 
Hibbard  Memorial  Volume  1,  Papers  on  PaJeontolngy.  No. 
10.  Museum  of  Paleontology,  University  of  Michigan,  Ann 
Arbor,  384  pages. 

LaRocque,  Aurele.  1966-70.  Pleistocene  Mollusca  of  Ohio.  BulL 
Dept.  Natural  Resources,  Ohio  62(M):l-800. 



Leslie  Hubricht 

4026  a5th  Street 
Meridian,  Mississippi  39301 


A  blind  cave  snail,  Amnicola  cora,  is  described  from  Independence  Co.,  Arkansas. 

Amnicola  cora,  new  species 

Figs.  1-3 

Description:  Shell  small,  broadly  conic,  wider 
than  high,  thin,  subhyaline,  pale-yellow;  whorls 
3.3,  well-rounded  the  last  whorl  lightly  appressed 
to  the  preceding  whorl,  sutures  very  deep, 
nuclear  whorl  slightly  raised;  umbilicus  open, 
about  one-fifth  the  diameter  of  the  shell;  aper- 
ture nearly  round,  peristome  continuous,  barely 
attached  to  the  preceding  whorl,  lip  thin,  col- 
umellar  margin  not  reflected  or  bent;  sculpture 
of  many  fine  spiral  lines,  operculum  comeus, 
multispiral,  with  about  5  whorls. 

Animal  white  and  blind,  without  any  trace  of 
eyes;  verge  bifid,  rather  stout;  central  tooth  of 
the  radula  with  11  denticles  on  the  reflection,  one 
moderately  large  mesocone  and  5  ectocones  on 
each  side;  lateral  tooth  with  11  denticles,  one 
moderately  large  mesocone,  3  entocones,  and  7  ec- 
tocones; marginal  teeth  with  numerous  small 

Height  1.6  mm,  diameter  2.0  mm,  aperture 
height  1.0  mm,  aperture  width  0.9  mm,  umbilicus 
diameter  0.4  mm,  3.3  whorls.  Holotype. 

Distribution:  ARKANSAS:  Independence  Coun- 
ty: .stream  in  Foushee  Case,  3  miles  west  of  Locust 
Grove  (Type  Locality)  (Norman  &  Jean  Young- 

steadt;  Leslie  Hubricht,  collectors)  holotype  193762, 
and  paratypes  193763,  Field  Museum  of  Natural 
History,  other  paratypes  47584,  47585,  collection  of 
the  author. 

Remarks:  Amnicola  cora  is  most  closely  related 
to  A.  stygia  Hubricht  from  cave  streams  in  Perry 
Co.,  Missouri.  It  differs  in  being  smaller,  with 
more  slowly  expanding  whorls,  the  shell  is  not  as 
fragile,  and  the  operculum  is  multispiral  rather 
than  paucispiral.  It  is  named  for  the  Attic  god- 
dess, Cora,  Queen  of  Hades. 


FIG.  1-3.  Amnicola  cora  Hubricht.  holotinw.  Fh-nwings  courtesy 
iif  Elisabeth  A.  Leibman.  Field  Museum  of  Nat  uraJ  History. 

Vol.94  (4) 

October  30, 1979 





K.  Elaine  Hoagland 

Department  of  Biology 

Lehigh  University 
Bethlehem,  Pa.  18015 


In  the  course  of  a  stiuiy  of  reproductive  energetics,  behavioral  observations  were 
made  on  Crepi'dula  fomicata  (Linnaeus),  C.  plana  Say,  and  C.  convexa  Say. 
Althoiigh  C.  convexa  is  intertidal,  C.  fomicata  and  C.  plana  rarely  are.  C.  fornicata 
orients  itself  on  convex,  exposed  surfaces  mth  the  anterior  shell  margin  upward,  if 
possible.  C.  plana  is  photonegative.  C.  fomicata  and  C.  convexa  juveniles  appear  at 
staggered  intervals  during  the  .summer  in  New  England. 

When  brooding  eggs,  females  of  all  three  species  are  sedentary.  However,  all  but 
the  highly  convex  or  tunsted  individ^ials  are  capable  of  some  movement.  C.  convexa 
is  the  most  mobile.  Only  C.  fomicata /orws  stacks  of  more  than  3  individuals. 

Brooding  is  energetically  costly  for  Crepidula,'  both  brood  abortion  and  brood 
cannibalism  occur.  Eggs  can  also  be  delayed  in  hatching.  Newly-hatched  C.  convexa 
graze  using  the  radxda;  filter-feeding  is  probably  not  efficient  at  that  stage. 

These  behavioral  patterns  are  discussed  in  terms  of  their  survival  advantages 
and  niche  differences  of  the  three  sympatric  species. 

There  are  three  species  of  Crepidula  found 
commonly  along  the  eastem  coast  of  the  United 
States:  C.  fomicata  (Linnaeus),  C.  convexa  Say, 
and  C.  plana  Say.  The  three  share  several  generic 
characters  of  an  ecological  nature:  they  are 
primarily  sedentary  as  adults,  they  must  copulate 
in  order  to  reproduce,  they  are  protandrous,  and 
they  acquire  food  via  filtration  of  water  through 
the  gills.  Species  differences  include  maximum 
size,  shell  convexity,  shell  muscle  scar  patterns, 
substrate  preferences,  and  whether  or  not  there  is 
a  planktonic  larval  stage  (Hoagland,  1977b).  The 
species  can  be  collected  together  at  many 
localities,  including  Woods  Hole,  Massachusetts. 

In  the  course  of  a  comparative  study  of  the 
reproductive  energetics  of  the  three  species 
(Hoagland,  1975),  behavioral  and  physiological 
differences  were  identified  that  give  each  species 
unique  niche  dimensions  (Hoagland,  1978;  1979). 
Tiis  paper  adds  further  observations  on  orienta- 
tion behavior,  brood  care,  and  feeding  in 
Crepidula.  After  discussing  each  set  of  observa- 
tions in  turn,  I  will  interpret  the  findings  in  the 
context  of  niche  theory  and  evolutionary  adapta- 

tions  for   the   survival   of   individuals   of  each 


Individuals  of  all  three  species  were  observed 
in  shallow  water  (less  than  1  m)  on  shell  and 
stone  substrate  resting  on  mud  or  sand  bottom, 
at  Vineyard  Haven  (Martha's  Vineyard)  and 
Woods  Hole,  Massachusetts.  Some  C.  fornicata  and 
C.  plana  were  found  attached  to  live  horseshoe 
crabs  (Limidus  polyphemus).  Many  C.  plana  and 
C.  convexa  were  on  gastropod  shells  occupied  by 
hermit  crabs,  while  C.  convexa  was  abundant  on 
live  Littorina  littorea.  C.  fomicata  was  also 
observed  on  stones  in  tide  pools  at  Nahant, 
Massachusetts,  and  on  Mytilus  edulis  attached  to 
docks  at  Tiverton,  Rhode  Island. 

Some  specimens  and  their  substrates  were 
marked  in  the  field  by  notching  the  shell  and 
painting  numbers  on  the  substrate.  Laboratory 
observations  were  made  on  specimens  taken  from 
the  Woods  Hole  and  Martha's  Vineyard  popula- 
tions. Live  specimens  still  attached  to  their 
original  substrates,  or  made  to  attach  to  watch 


Octobers  1979 

Vol.94  (4) 

glasses,  were  maintained  in  flowing  sea  water 
tables  at  the  Woods  Hole  Oceanographic  Institu- 
tion. The  temperature  was  not  controlled. 



Many  ecologists  describe  Crepidula  as  inter- 
tidal.  C.  convexa  occurs  on  shells  of  Littonun  lit- 
torea  and  Uyanassu  obsoleta,  snails  that  frequent- 
ly exist  intertidally.  C.  convexa  may  be  found 
with  a  bone-dry  shell,  tightly  affixed  to  an  equal- 
ly dry  living  snail,  during  the  hottest  summer 
days.  Yet  C.  convexa  has  been  dredged  from  a 
depth  of  212  meters  (Abbott,  1974). 

However,  C.  fiyniicata  and  C.  plana  are  uncom- 
mon above  the  mean  low  tide  line.  In  Nahant,  C. 
fomicata  is  found  in  upper  tide  pools,  but  only 
occasionally  are  specimens  found  out  of  water.  In 
Woods  Hole,  the  only  specimens  of  C.  fomicata  or 
r.  plana  found  out  of  water  in  three  years  of 
study  were  those  deposited  ashore  by  storms  or 
by  the  buoyant  alga,  Codium  fragile,  which  at- 
taches to  the  shells  of  C.  fomicata  and  floats  the 
snails  to  the  intertidal  zone.  Those  C.  fn-mcata 
and  C.  plana  that  attach  to  the  undersides  of 
horseshoe  crabs  or  inside  hermitcrab-occupied 
shells  also  find  their  way  into  the  intertidal  zone, 
but  remain  in  a  moist  environment. 

None  of  the  Crepidula  are  commonly  found  on 
hard  substrate  in  the  rocky  intertidal  zone;  this 
high  energy  environment  is  apparently  not  suited 
to  their  mode  of  life,  which  is  much  closer  to  the 
oyster  than  to  either  the  limpet  or  the  mussel. 
The  preferred  substrate  of  C.  fomicata  is  a  con- 
vex surface,  not  highly  irregular.  Specimens  are 
rarely  found  on  large  boulders,  but  are  common 
on  fist-sized  stones.  The  bottom  sediments  are 
usually  mud  rather  than  sand;  the  latter  in- 
dicates an  environment  that  is  poor  in  organic 
material  and  probably  in  food  for  filter  feeders. 
C.  fornirata  is  known  for  forming  large  stacks, 
one  animal  atop  the  other  (Figure  1).  Occupying 
such  a  convex  surface,  a  C.  fomicata  individual 
would  be  exposed  to  greater  currents  and  less 
sedimentation  than  if  it  were  located  on  a  con- 
cave surface. 

In  the  laboratory,  young  specimens  of  C.  for- 
ninitd  placed  inside  of  finger  bowls  invariably 
climb  up  and  over  the  edge  of  the  bowl,  to  the 

FIG.  1.  A  Mfifk  of  Crepidula  fomicata  in  life  position.  Sexes 
(if  the  indimlualx  are  indicated.  I  =  intermediate. 

convex  exterior.  The  final  orientation  is  nearly 
always  as  shovm  in  Figure  2.  The  animal  sits  at 
an  angle  to  the  top  of  the  bowl,  with  its  anterior 
shell  margin  directed  upward,  near  or  flush  with 
the  rim  of  the  bowl.  Faeces  and  pseudofaeces  are 
releiised  from  the  anterior  shell  margin.  Mobile 
('.  fiirnmiln  also  tend  to  move  to  the  part  of  the 
tank  with  the  most  rapid  water  flow. 

C.  convexa  has  no  preference  for  convex  or  con- 
cave surfaces,  nor  does  it  show  precise  orienta- 
tion. It  forms  male-female  pairs,  but  not  stacks. 
It  attaches  to  eelgrass  blades  as  easily  as  to  shells, 
bottles,  or  porcelain  (Hoagland,  1977a). 

C.  plana  prefers  dark  places  and  concave  or 
flat  surfaces,  such  as  underneath  rocks  or  inside 
large  empty  shells.  It  forms  clusters  of  several 
males   and  juveniles   on   one   female,   but    not 

FIG.  2.  Preferred  orientation  of  Crepidula  fornicata  on  the 
iiutxide  of  a  ylaxa  fingerhowl.  The  anterior  maiyin  touches  the 
nm  of  the  hold.  Die  entire  bowl  wm  submeryed  in  sea  miter. 

Vol.94  (1) 

October  30, 1979 


stacks.  In  the  laboratory,  C.  plana  juveniles 
display  a  photonegative  response.  Natural  con- 
cave surfaces  tend  to  be  inner  surfaces,  so  it  is 
not  clear  if  C.  plana  is  selecting  darkness  or  con- 
cavity or  both. 

All  three  species  are  sometimes  found  on  the 
same  piece  of  substrate,  such  as  a  stone  or  a  dead 
shell.  C.  plana  occupies  the  under-  or  inside  of 
such  a  substrate,  but  the  microhabitats  of  C.  for- 
nicata  and  C.  convexa  cannot  be  so  easily 
distinguished.  In  Woods  Hole  in  the  years 
1972-1974,  the  summer  reproductive  periods  of  C. 
foniicata  and  C.  convexa  did  not  coincide.  C.  for- 
nicata  spat  settled  in  early  June,  followed  by  a 
"set"  of  barnacles;  then  C.  convexa  juveniles  ap- 
peared in  early  July.  Another  wave  of  C.  for- 
nicata  settled  in  August,  and  finally  more  C.  con- 
vexa in  early  fall.  This  pattern  serves  to  decrease 
competition  among  juveniles  for  substrate.  Those 
individuals  of  both  C.  fomicata  and  C.  convexa 
that  settled  intertidally  disappeared  within  a  few 
days.  This  indicates  either  mortality  or  removal 
to  a  less  exposed  microhabitat. 


The  common  knowledge  among  ecologists  is 
that  Crepidula  species  are  largely  sedentary.  Yet 
Crepidula  must  copulate,  and  the  substrates  of 
Crepidula  are  spatially  discontinuous;  the  snails 
cannot  survive  in  the  intervening  sand  or  mud.  C. 
fonmata  and  C.  plana  can  disperse  during  the 
planktonic  larval  stage,  but  C.  convexa  lacks  this 
stage.  I  investigated  the  mobility  of  the  three 
species,  to  see  how  wide  is  their  access  to  the 
substrate  and  to  each  other. 

In  the  field,  C.  fomicata  and  C.  plana  adults 
are  largely  sedentary.  Of  50  female  C.  fonmata 
marked  in  the  tidepools  of  Nahant,  34  remained 
in  place  two  years  later.  C.  plana  and  C.  convexa 
were  more  difficult  to  follow  because  their 
substrates  moved.  However,  C.  convexa  adults 
were  observed  to  travel  within  tidepools.  Those 
living  on  eelgrass  either  had  to  move  or  perish, 
because  the  eelgrass  died  each  winter.  The  greater 
mobility  of  ('.  c(iinr.m.  and  its  greater  propensity 
for  attaching  to  living  organisms,  means  that  C. 
convexa  is  more  likely  to  disperse  as  an  adult 
than  either  of  the  other  species.  However,  C.  con- 
vexa, like  all  other  Crepidula,  is  sedentary  when 
out  of  water. 

Laboratory  observations  confirmed  the  above 
impressions.  Small  individuals  of  all  three 
species,  including  most  C.  convexa,  can  maneuver 
over  abrupt  discontinuities  in  substrate  (e.g., 
from  one  stone  to  another),  across  a  silty  tank 
bottom,  as  long  as  there  is  a  hard  bottom  under- 
neath. Movement  can  be  assessed  by  measuring 
trails  left  on  the  silty  bottom.  Adult  C.  fornicata 
and  C.  plana  grow  to  fit  the  curvature  of  the 
substrate,  and  have  difficulty  moving.  Highly 
arched  or  distorted  specimens  cannot  move  at  all. 
Regardless  of  species,  those  brooding  young  do 
not  move. 

Both  C.  fomicata  and  C.  convexa  have  a 
tendency  to  climb  up  (negative  geotropism)  and 
out  of  the  water  when  placed  in  aquaria.  They 
often  sit  above  the  water  line,  where  they  die. 
This  tendency  can  be  reduced  by  increasing  aera- 
tion in  the  tanks.  In  fact,  several  times,  young  C. 
fomicata  established  themselves  directly  on  top 
of  an  air  stone.  When  aeration  in  the  tanks  was 
stopped,  all  but  the  brooding  females  and  those 
attached  to  other  highly  arched  shells  moved  up- 

The  ability  of  the  three  species  of  Crepidula  to 
regain  their  positions  on  a  substrate,  once 
dislodged,  is  very  different.  C  convexa  can  re- 
attach within  seconds,  if  both  animal  and 
substrate  are  wet.  C.  convexa  has  a  very  active 
and  flexible  foot,  which  allows  an  overturned 
animal  to  right  itself.  I  have  observed  C.  convexa 
floating  upside-down  on  the  surface  film  of  the 
water  until  reaching  the  side  of  the  tank,  where 
it  quickly  attached. 

Adult  C  fomicata  and  C.  plana  may  take  1  to 
3  hours  to  attach  firmly  to  a  substrate.  During 
that  time,  the  specimens  are  vulnerable  to  crab 
predation.  I  demonstrated  this  vulnerability  by 
placing  several  adult  Crepidula  loose  on  top  of 
their  former  substrates,  accompanied  by  3  crabs, 
in  an  aquarium.  All  specimens  of  Crepidula  were 

The  difference  in  ease  of  attachment  between 
species  is  partly,  but  not  completely,  due  to  size. 
Small  C.  fomicata  and  C.  plana  can  attach  more 
effectively  than  larger  ones,  which  often  have 
irr^ularly-shaped  apertures  that  can  only  fit 
against  the  substrate  on  which  they  grew.  Still, 
small  specimens  of  C.  convexa  were  more  resil- 
ient and  active  than  their  counterparts. 


October  30, 1979 

Vol.94  (4) 

One  cause  for  mobility  in  Crepidula  is  to 
enhance  breeding  success  by  ensuring  copulation. 
In  both  field  and  laboratory,  C.  convexa  and 
C.  plana  males  were  seen  to  wander  from  one 
female  to  another,  although  a  single  pairing  of 
C.  convexa  in  the  lab  lasted  as  long  as  5  months. 
Some  C.  fomicata  males  also  wander,  but  some 
spend  their  entire  lives  as  males  with  one  stack 
of  females.  Most  biologists  have  assumed  that 
stacking  in  C.  firmicata  is  related  to  mating. 
Walne  (1956)  believed  that  the  tendency  to  form 
stacks  was  not  related  to  reproduction,  but  rather 
to  the  production  of  feeding  currents.  The 
strength  of  the  excurrent  flow  of  faeces  and 
pseudofaeces  may  be  augmented  by  the  shape  of 
the  stack,  as  Walne  supposed.  No  data  exist  on 
this  point.  An  analogy  might  be  made  to  oysters, 
which  form  clusters  that  serve  to  raise  the 
animals  from  a  muddy  substrate,  augmenting 
their  ability  to  filter-feed.  Yet  in  Crepidula,  the 
stack  is  a  breeding  unit  (Hoagland,  1978),  and 
probably  reduces  the  vulnerability  of  males  to 
predation  by  reducing  their  need  to  be  mobile. 
Because  of  the  close  proximity  of  the  right 
anterior  portions  of  the  shells  of  a  stack  (Figure 
1),  the  several  males  at  the  top  can  easily 
copulate  with  the  several  females  at  the  bottom, 
with  eight  or  more  individuals  in  between.  This 
leads  to  a  promiscuous  breeding  system,  as  is  also 
found  in  C.  convexa  and  C.  plana,  but  by  means 
of  an  entirely  different  behavior  pattern. 

Brood  Care 

All  female  Crepidula  brooding  young  are  com- 
pletely sedentary.  Interesting  problems  for 
ecologists  include  just  how  much  of  a  liability 
this  is  for  a  brooding  female.  How  much  energy 
is  expended  by  a  brooding  female  in  caring  for 
the  eggs?  Does  brooding  affect  her  own  chances 
for  survival? 

I  observed  that  females  of  all  three  species,  but 
especially  C.  fomicata,  often  push  the  young  out 
from  under  the  shell  when  aeration  is  reduced, 
measurably  lowering  the  oxygen  tension  in  the 
aquarium.  The  same  event  occurs  when  the 
animals  are  kept  in  millipore-filtered  sea  water 
(starvation).  In  three  of  eight  cases  of  low  oxygen 
and  two  of  six  cases  of  starvation,  the  females 
died  after  expelling  the  eggs.  Survival  of  females 
of  equivalent  size  but  not  br(x)ding  eggs  was  bet- 

ter in  all  three  experimental  situations,  but  in- 
sufficient data  were  obtained  for  statistical 
analysis.  The  data  suggest  that  there  is  a  cost  in- 
volved in  brooding,  and  that  a  female  might  abort 
a  bnxjd,  thereby  increasing  her  longevity. 

Egg  masses  released  by  females  were  kept  in 
aerated  but  unfiltered  sea  water  to  see  if  they 
would  hatch.  Ciliated  protozoans,  bacteria,  and 
nematodes  infested  most  of  the  egg  masses.  If 
some  of  the  eggs  become  inviable,  the  entire  egg 
mass  eventually  was  lost  to  the  predators. 
However,  2  of  10  ^g  masses  of  C.  convexa  and  4 
of  20  of  C  fomicata  did  hatch.  The  young  were 
normal  in  appearance.  Therefore,  release  of  the 
brood  by  a  dying  female  could  be  of  benefit  to  the 
young,  especially  if  they  were  near  hatching. 

The  role  of  the  female  in  larval  brooding  thus 
appears  to  be  related  to  oxygenation  and  cleaning 
of  the  larvae.  Egg  maintenance  appears  to  re- 
quire continuous  circulation  of  water.  A  female 
without  eggs  reduces  its  filtration  if  the  water 
contains  no  food,  but  one  brooding  eggs  continues 
to  filter  at  a  high  rate.  This  is  one  energ>'  cost. 
The  brood  is  maintained  in  the  vicinity  of  her 
gills,  which,  in  these  filter-feeders,  create  strong 
currents  flowing  over  the  egg  mass  (Werner, 
1951).  The  presence  of  the  egg  mass  probably 
reduces  the  efficiency  of  the  gills  as  respiratory 
and  feeding  structures;  this  is  another  cost  of 

Not  only  can  individuals  of  Crepidula  be  in- 
duced to  leave  their  broods,  but  they  can 
sometimes  be  induced  to  produce  eggs  at  ab- 
normal seasons.  In  the  laboratory,  they  can  also 
retain  broods  over  winter,  but  this  has  not  been 
observed  in  nature,  at  least  in  New  England 
where  reproduction  normally  occurs  only  in  sum- 
mer. In  New  England  waters,  Crepidula  do  not 
develop  broods  until  the  temperature  exceeds  10° 

Specimens  of  C.  fomicata  collected  at  Martha's 
Vineyard  in  December  1972,  were  accidently  left 
outside  a  water  table,  in  a  finger  bowl,  sometime 
between  January  18  and  February  1,  1973.  The 
water  warmed,  and  two  females  produced  eggs. 
The  females  with  broods  were  placed  back  in  the 
water  table,  where  the  water  temperature  was  2  - 
4°  C.  The  egg  masses  finally  hatched  on  April  1, 
1973,  at  a  temperature  of  6°  C.  Another  specimen 
dredged     from     Buzzard's     Bay,     at     a     time 

Vol.94  (4) 

October  30, 1979 


unrecorded,  spawned  in  a  water  table  on 
February  13,  1973,  when  the  water  temperature 
suddenly  rose  to  6°  C.  In  the  summer  of  1972,  25 
female  C.  fomicata  were  maintained  at  9°  C,  to 
see  if  egg  production  could  be  delayed.  None  pro- 
duced eggs  at  9°  during  a  three-month  period, 
June  to  August,  when  C.  fomicata  is  normally 

Specimens  taken  from  Martha's  Vineyard  in 
November,  1972,  contained  ripe  gonads; 
specimens  taken  from  the  same  locality  in 
January,  1973,  had  spent  gonads,  although  no 
reproduction  was  observed  in  the  interim.  The 
gonads  are  probably  resorbed  during  winter 
under  natural  conditions. 

Another  question  of  interest  is  how  long  sperm 
can  be  stored  within  the  seminal  receptacle  of 
the  female.  Coe  (1953)  claimed  that  sperm  storage 
could  last  several  months  to  a  year.  In  my 
laboratory,  females  of  C.  fomkata  known  to  have 
mated  but  isolated  in  early  June  continued  to 
reproduce  broods  through  September,  but  none 
reproduced  the  following  spring.  This  may  have 
been  due  to  sub-optimal  feeding  in  the 
laboratory.  Orton  (1952)  suggested  that  an  in- 
dividual could  store  its  own  sperm  while  in  the 
process  of  changing  sex,  thereby  functioning  as  a 
self-fertilizing  hermaphrodite,  but  his  speculation 
was  based  on  the  circumstantial  evidence  of  find- 
ing isolated  females  with  broods. 

Larval  Cannibalism 

It  had  been  thought  that  Crepidula  under  nor- 
mal circumstances  did  not  provide  the  developing 
young  mth  nurse  cells  (Fretter  and  Graham, 
1962,  p.  404-405).  However,  Gallardo  (1977)  has 
reported  nurse  cells  for  Crepidida  dilatata,  and 
Coe  (1942),  for  C  onux.  Thorson  (1940)  said  that 
some  capsules  of  C.  walshi  contained  large  em- 
bryos, while  other  embryos  in  the  same  capsules 

An  examination  of  several  hundred  broods 
each  of  C.  fomicata  and  C.  convexa  within  24 
hours  of  collection  in  the  field  revealed  that  a 
high  percentage  (10%  of  C.  fomicata;  23%  of  C. 
convexa)  failed  to  develop.  These  embryos  broke 
up  and  were  ingested  by  other  embryos  once  they 
had  reached  the  stage  of  possessing  feeding  struc- 
tures. If  a  normal  embryo  was  artificially  rup- 
tured  with   a   fine   needle,   surrounding   larvae 

spinning  around  within  the  egg  capsule  drew 
cells  from  the  damaged  embryo  into  their  gullets 
via  a  self-generated  feeding  current.  Both  species 
did  this,  but  C.  convexa  appeared  not  to  have  the 
capability  once  the  larvae  had  lost  the  velum.  If 
the  damaged  larva  is  in  the  veliger  stage,  the 
velum  is  not  eaten  but  persists  within  the  egg 
capsule  until  the  capsule  ruptures  at  hatching. 

This  process  probably  explains  the  cases  I  have 
seen  in  C.  convexa  where  some  hatching  egg  cap- 
sules of  a  brood  contain  8-10  uniform,  average 
size  young,  whereas  others  contain  2-3  very  large 
young.  It  explains  Thorson 's  observation  as  well. 
The  size  at  hatching  is  more  uniform  in  C.  for- 
nicata,  which  releases  its  brood  in  the  veliger 


When  the  broods  are  released,  C.  convexa 
young  immediately  begin  a  benthic  existence.  In 
the  laboratory,  I  observed  one  brood  of  newly 
hatched  young  moving  over  a  glass  substrate 
coated  with  bacteria  and  microscopic  algae.  The 
snails'  heads  swayed  from  side  to  side,  clearing 
tracks  of  microorganisms  and  debris.  Inspection 
under  the  dissecting  microscope  showed  that  the 
odontophores  and  radulas  were  working,  and 
material  was  entering  the  guts  of  the  animals. 
Putnam  (1964)  reported  that  C.  adunca  also  uses 
its  radula  to  graze  when  first  emerging  from  the 
egg  capsule.  Microscopic  examination  of  the  gill 
filaments  of  newly  hatched  C.  convexa  proved 
them  to  be  fewer  in  number  than  in  adults  and 
rather  fat  and  club-shaped.  It  is  doubtful  that 
they  could  function  efficiently  as  filtering  devices 
at  that  stage.  This  is  probably  one  reason  that 
Crepidula  retains  a  large,  well-developed  if 
unspecialized  radula,  despite  the  filter-feeding 

Another  reason  for  retention  of  the  radula 
(over  evolutionary  time)  is  that  it  is  used  to  han- 
dle food  packaged  on  the  gills  (Werner,  1951).  I 
have  observed  adults  of  C.  fomicata  to  reach 
around  and  grab  mucous  balls  containing  large 
particles  rejected  by  the  gills  (pseudofaeces), 
which  normally  exit  on  the  right  side  of  the  man- 
tle cavity.  Occasionally,  these  balls  are  re- 
ingested.  This  behavioral  pattern  was  observed 
only  in  closed-system  aquaria,  where  I  assume 
food  availability  was  low. 


October  30, 1979 

Vol.94  (4) 

Evolutionary  Adaptations 

Although  cause-and-effect  relationships  are  dif- 
ficult to  determine  in  evolutionary  biology,  one 
can  often  guess  the  survival  value  of  a  particular 
behavior  or  morphological  structure.  In  the  case 
of  Crepidula.  it  is  clear  that  individual  orienta- 
tion is  adaptive.  In  C.  fomicata,  it  maximizes  the 
chances  of  encountering  others  of  the  same 
species  and  maximizes  feeding  currents  while 
minimizing  fouling.  In  C.  plana,  an  orientation 
opposite  to  C.  fomicata  with  respect  to  light 
sacrifices  availability  of  currents,  but  increases 
protection  against  large  predators  such  as  crabs 
and  fish.  In  C  conveia.  small  size  and  foot  flex- 
ibility allow  much  greater  mobility,  an  obvious 
advantage  in  a  species  without  planktonic  larvae. 

Brooding  costs  the  female  an  as-yet  undeter- 
mined amount  of  energy.  The  expulsion  of  the 
broods  under  conditions  of  stress  benefits  the 
female  by  saving  energy,  and  may  indirectly 
benefit  the  offspring,  which  would  die  if  trapped 
under  a  dead  female.  In  terms  of  evolutionary 
theory,  this  is  the  optimal  strategy  for  an  in- 
dividual that  has  high  risk  of  juvenile  mortality, 
can  produce  numerous  broods  over  its  lifetime, 
and  that  increases  in  fecundity  with  age  and  size. 
The  same  strategy  occurs  in  birds  that  abandon 
the  nest  under  unfavorable  conditions. 

The  survival  advantage  of  brood  cannibalism  is 
even  more  obvious.  This  system  prevents  wastage 
pf  the  energy  that  the  female  diverted  into 
reproduction.  Furthermore,  nonviable  embryos  do 
not  remain  to  decay  and  contaminate  the  brood. 
The  "nurse  cells"  are  not  specially  differentiated 
as  such,  but  the  effect  is  the  same.  Fretter  and 
Graham  (1962,  p.  405)  described  the  situation 
structurally:  "In  capsules  in  which  embryos  are 
not  separated  from  one  another  but  share  a  com- 
mon supply  of  albumen,  it  seems  likely  that  a 
healthy  individual  will  automatically  devour 
disintegrating  tissues  with  the  albumen  which  is 
used  as  f(X)d."  In  terms  of  evolution,  this  is  a  way 
of  increasing  offspring  size,  as  an  alternative  to 
the  female  adding  more  yolk  to  all  the  eggs.  The 
advantage  of  size  to  a  young  Crepidula  is  not 
known,  but  by  analogy  to  other  organisms,  it 
probably  provides  an  edge  in  survival. 

Niche  Theory 

The  three  species  of  Crepidula  from  New 
England  are  the  most  divergent,  morphologically 
and  behaviorally,  of  those  living  in  the  Atlantic 
Oceaa  The  differences  among  sympatric  species 
in  microhabitat,  mobility,  and  orientation 
preferences  bring  up  questions  about  how  they 
divide  their  resources  (Schoener,  1974).  Hoagland 
(1976)  pointed  out  that  in  Crepidula,  species  with 
morphological  and  ecological  parameters  in  com- 
mon overlap  only  in  the  tropics  where  there  is 
closer  species  packing.  In  rigorous  environments 
such  as  the  northwestern  Atlantic,  there  are 
found  the  fewest  species,  with  the  greatest  mor- 
phological and  ecological  distance  between  them. 
Important  niche-discriminating  parameters  were 
identified  as  substrate  type,  light  preference, 
depth  preference,  and  a  size  factor,  correlated 
with  types  of  life  history  and  types  of  predators. 

Carpenter  (1857)  also  demonstrated  that  the 
number  of  sympatric  species  of  Crepidula,  and 
the  family  Calyptraeidae  as  a  whole,  decreases 
dramatically  with  increasing  latitude  along  the 
west  coast  of  North  America.  Similarly,  in  the 
Atlantic,  those  from  the  northernmost  part  of  the 
province  have  the  most  extreme  differences  in 

Reproductive  isolating  mechanisms  are  an 
alternative  to  competition  as  an  explanation  for 
the  observed  differences  between  related  species. 
However,  the  need  for  such  mechanisms  should 
increase  in  the  tropics,  and  instead,  this  is  the 
area  with  the  most  similar  congeners.  I  conclude 
that  the  present  distribution  of  Crepidula  in  the 
Northwestern  Atlantic  and  the  behavioral  dif- 
ferences of  sympatric  species  are  indicative  of 
divergence  that  occurred  long  ago  and  had  the 
effect  of  decreasing  competition. 


I  thank  P.  Ander,  G.  M.  Davis,  T  Schoener, 
and  R.  D.  Turner  for  stimulating  discussion  of 
much  of  this  material.  G.  Grice  provided  labora- 
tory space  at  the  Woods  Hole  Oceanographic 
Institution.  G.  M.  Davis  and  R.  Robertson  read  and 
commented  on  the  manuscript.  This  work  was 
supported  in  part  by  a  Gibbs  Fellowship  from 
Harvard  University. 

Vol.94  (4) 

October  30, 1979 



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Nostrand.  New  York.  663  pp. 
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knowledge  with  regard  to  the  Moliusca  of  the  west  coast  of 

North  America.  Report  of  the  Brit.  Assoc,  for  the  Adv.  of 

Sci  for  1856:  159-368.  pis.  6-9. 
Coe,  W.  R.  1942.  The  reproductive  organs  of  the  prosobranch 

mollusk  Crepidula  onyi  and  their  transformation  during 

the  change  from  male  to  female  phase.  Jour,  of  Morphology 

70:  .501-512. 
1953.    Influences   of  association,   isolation,   and 

nutrition  on  the  sexuality  of  snails  of  the  genus  Crepidida. 

Jour,  eiper.  ZooL  122:  5-19. 
Fretter,    V.    and    A.    Graham.    1962.    British    Prosobranch 

Molhiscs.    their  Functional   Anatomy  and  Ecology.    Ray 

Society,  London,  xvi  +  755  pp. 
Gallardo.  C.  S.  1977.  Two  modes  of  development  in  the  mor- 

phospecies  Crepidula  dilatata  from  Southern  Chile.  Marine 

B>o/(x/.v  39:241-251. 
Hoagland,  K.  E.  1975.  Reproductive  strategies  and  evolution 

in  the  genus  Crepidula  (Gastropoda:  Calyptraeidae).     Ph.D. 
Diss..  Harvard  University.  360pp. 
1976.  Patterns  of  evolution  and  niche  partitioning 

in  North  American  Crepidula  (Gastropoda:  Calyptraeidae). 

A.M.U.  Bull,  for  1975:b2-^. 

1977a.  A  gastropod  color  polymorphism:  one  adap- 

.  1977b.  Systematic  review  of  fossil  and  Recent 

Crepidula  and  discussion  of  evolution  of  the  Calyptraeidae. 
Malacologia  16:a53420. 

1978.  Protandry  and  the  evolution  of  environ- 
mentally-mediated sex  change:  a  study  of  the  Moliusca. 
M(U(woiogia  17:365-.391. 

.   (1979).  The  behavior  and   physiology  of  three 

five   strategy   of   phenotypic    variation.    Biol.    Bull.    152: 

species  of  Crepidida  exposed  to  a  desiccating  environment. 

Ms  submitted  to  The  Veliyer. 
Orton.  J.  H.   1952.  Protandry  with  self-fertilization  in  the 

American  slipper  limpet  Crepidula  fomicata.  Nature  169: 

Putnam,  D.  A.  1964.  The  dispersal  of  young  of  the  commensal 

gastropod  Crepidula  adunca  from  its  host  Tegula  funebralis. 

The  W/jger6(Suppl.):63-66. 
Schoener,  T.  W.  1974.  Resource  partitioning  in  ecological  com- 
munities. .Sc!>«ff  185:27-.39. 
Thorson,   G.    1940.   Studies  on   the   egg   masses  and   larval 

development  of  Gastropoda  from  the  Iranian  Gulf.  Danish 

sci.  Invest.  Iran  2:159-238. 
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the  distribution  of  the  larger  epibenthonic  invertebrates. 

Pish.  Invest.  London  Ser.  II.  20  (6):l-50. 
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John  J.  Jenkinson' 

Museum  of  Zoology 
Ohio  State  University 
Cblumbus.  Ohio  43210 

The  introduction  and  spread  of  the  Asiatic 
Clam,  Corhicvla  manilensis  (Philippi,  1841)^  in 
the  United  States  has  been  recorded  by  numerous 
authors  (review  in  Sinclair,  1971;  Sickel,  1973; 
Fuller  and  Powell,  1973;  Diaz.  1974;  Britten  and 
Murphy,  1977).  These  papers  generally  include 
the  type  of  substrate  in  which  the  animals  were 

'  Present  address:  T.V.A..  Forestry  Building,  Norris,  TN  37828. 
'  In  this  paper  I  am  following  present  usage  by  considering 
C  manilensis  (Philippi,  1841)  to  be  the  name  of  the  eastern 
North  American  corbiculid  species.  Morrison,  however,  be- 
lieves that  the  vast  majority  of  these  populations  are  C.  leana 
Prime,  1864  (J.  P.  E.  Morrison,  pe?-.S((«a/  communication.  1977). 

found;  the  range  of  size  classes  (often  used  to 
suggest  the  date  of  the  introduction);  some  men- 
tion of  the  problems  that  this  exotic  bivalve  will 
cause  to  human  uses  of  the  watercourse;  and,  oc- 
casionally, some  hypothesis  or  comment  as  to  how 
Corbicula  might  have  been  introduced  into  the 
system.  Few  of  these  papers  detail  the  extent  of 
the  newly  reported  Corbicula  population,  a  fact 
which  could  indicate  a  great  deal  about  the  in- 
troduction of  this  animal  into  the  stream  and  its 
subsequent  spread  within  the  system. 

Distributional    data    about    previously    unre- 


October  30, 1979 

Vol.  94  (4) 

ported  Corhicula  populations  were  collected  while 
studying  the  distribution  patterns  of  unionids  in 
east-central  Alabama  (Jenkinson,  1973:  1975). 
This  study  (conducted  in  1972  and  1973)  involved 
four  small  stream  systems,  all  of  which  originate 
in  central  Lee  County,  Alabama.  Two  of  these 
streams,  Saugahatchee  (Saw-ga-hach'-ee)  and 
Uphapee  (You-fap'-ee)  creeks,  flow  west  into  the 
Tallapoosa  River  while  the  other  two  streams, 
Halawakee  (Hal-a-wok'-ee)  and  Uchee  (Ooch'-ee) 
creeks,  flow  east  into  the  Chattahoochee  River 
(Fig.  1).  During  the  course  of  this  study  2,646 
unionids  and  76  voucher  specimens  of  Corhicula 
were  ajllected  from  47  productive  sites  on  these 
four  streams.  Additional  collections  have  also 
been  made  in  adjacent  small  streams  and  in  the 
two  rivers. 

Tlie  resulting  distribution  pattern  for  Cor- 
hicula is  illustrated  in  Figure  1.  Corhicula  is 
abundant  in  both  the  Tallapoosa  and  Chattahoo- 
chee rivers  (although  I  had  not  found  it  in  the 
Tallapoosa  River  in  1968),  however,  Corhicula  is 
essentially  absent  from  the  tributary  streams. 

Uchee  Creek  Population 

Two  exceptions  to  this  general  distribution  pat- 

tern were  found  to  exist.  One  large  and  apparent- 
ly well-established  population  of  Corhicula  was 
located  in  the  lower  half  of  Little  Uchee  Creek 
and  in  Uchee  Creek  only  below  the  mouth  of  Lit- 
tle Uchee  Creek.  No  Corhicula  specimens  were 
taken  in  any  other  part  of  this  creek  system 
although  unionids  were  abundant  in  all  of  the 
peiTTianent  streams.  The  farthest  upstream  collec- 
tion of  Corbicula  from  Little  Uchee  Creek  was 
taken  at  the  base  of  a  rapids  and  falls  that  mark 
the  transition  from  Piedmont  to  Coastal  Plain 
substrates.  This  was  also  the  most  upstream  site 
where  fishermen  were  noticed.  Following  the 
hypothesis  advanced  by  Sickel  (1973),  it  would  be 
tempting  to  suggest  that  Corbicula  was  in- 
troduced into  the  Uchee  Creek  system  at  this  site 
by  fishermen.  Unfortunately,  I  have  no  additional 
evidence  to  support  such  a  hypothesis. 

A  similar  distribution  pattern  for  Corbicula 
has  been  reported  from  the  Mesilla  Valley  of 
Texas  and  New  Mexico  (Metcalf,  1966).  In  that 
case  Corbicula  occurred  in  the  main  channel  of 
West  Drain  but  not  in  its  tributaries  or  in  any 
other  adjacent  tributary  of  the  Rio  Grande  River. 
Metcalf  suggested  that  the  periodic  drying  up  of 

FIG.  1.  The  Icnitwn  di.itributinn  o/ Corbicula  manilensis  (Philippi.  ISil).  in  eaxt-fentml  Alabama.  Most  recorxk  date  from  1972 
and  197S:  Sauyahaichee  Creek  records  aboxte  the  mouth  of  Loblockee  Creek  date  from  12  September  1976. 

Vol.  94  (4) 

October  30, 1979 


the  Rio  Grande  or  some  adverse  environmental 
factors  in  the  unpopulated  drains  might  account 
for  this  pattern.  Neither  of  these  conditions 
seems  to  be  operating  in  the  Uchee  Creek  system; 
the  larger  streams  always  maintain  some  min- 
imum flow,  and  any  "adverse  environmental  fac- 
tors" which  might  prevent  colonization  by  Cor- 
bicula  have  not  affected  the  thriving  unionid 

Saugahatchee  Creek  Population 

The  Uchee  Creek  population  was  the  only  Cnr- 
bicula  population  known  from  any  of  these  creek 
systems  until  October  1973,  when  John  C.  Hurd 
collected  one  dead  specimen  of  Corbicula  in 
Saugahatchee  Creek.  This  find  was  unexpected 
because  Hurd  had  surveyed  the  aquatic  mollusks 
of  western  Lee  County  in  1970-1971  and  had 
found  no  living  bivalves  in  the  main  stream  of 
Saugahatchee  Creek  (Hurd,  1971).  Hurd  had  con- 
cluded that  unionids  were  unable  to  survive  in 
Saugahatchee  Creek  because  this  stream  carries 
the  effluents  of  a  large  textile  mill  and  a  sewage 
treatment  plant. 

In  addition  to  the  mill  and  sewage  effluents, 
Saugahatchee  Creek  also  receives  water  from  the 
experimental  ponds  of  Auburn  University 
Department  of  Fisheries  and  Applied  Aquacul- 
ture.  During  the  summer  of  1972  a  project  was 
conducted  in  some  of  these  ponds  to  determine  if 
Corbicula  could  be  used  as  a  biological  filter  to 
reduce  the  plankton  levels  in  commercial  catfish 
ponds.  At  the  end  of  that  project  the  clay  bottoms 
of  the  test  ponds  were  screened  in  Saugahatchee 
Creek  to  separate  out  the  Corbicula  for  counting 
and  growth  analysis.  The  dead  specimen  that 
Hurd  collected  some  distance  downstream  during 
the  following  fall  might  have  been  an  escape  or  a 
discard  from  this  screening  process.  Regardless  of 
the  origin  of  this  specimen,  collections  made  in 
November  1973  indicated  that  living  Corbicula 
did  exist  in  Saugahatchee  Creek  at  that  time. 

Starting  with  the  collections  made  in  Novem- 
ber 1973,  three  sites  on  Saugahatchee  Creek  have 
been  sampled  at  approximately  18-month  inter- 
vals in  an  attempt  to  monitor  the  status  of  the 
Corbicula  population  in  this  stream.  The  most 
upstream  of  these  sites  is  located  appro.ximately 
one  kilometer  above  the  experimental  pond 
discharge  and  the  area  where  the  pond  bottoms 

Ikm,   upstream  Hm-   downstream  10km.   downstream 

HG.  2.  Girbicula  ciiUectiim  results  from  three  sites  an 
Saugahatchee  Creek  taken  over  a  three-year  period.  Numbers 
along  each  ordiimte  refer  to  maximum  shell  length  in 
millimeter's:  those  along  each  abscissa  refer  to  numbers  of  in- 
diiiduals  with  a  given  shell  length. 

were  screened.  The  midstream  site  is  approx- 
imately one  kilometer  below  the  screening  site 
and  the  downstream  site  is  approximately  nine 
kilometers  further  downstream.  In  addition  to  be- 
ing visited  in  November  1973,  all  three  sites  were 
collected  on  8  March  1975  and  on  12  September 
1976.  On  each  occasion  a  hand  seive  was  used  to 
collect  Corbicula  specimens  from  sandy  areas  in 
the  substrate.  No  special  effort  was  made  to  col- 
lect particular  size  classes;  what  was  desired  was 
an  essentially  random  sample  of  any  living  Cor- 
bicula population.  The  results  of  these  collections 
and  the  lengths  of  the  living  Corbicula  specimens 
obtained  are  shown  in  Figure  2. 

These  collections  document  that  during 
November  1973  a  population  of  relatively  small 
(<16mm)  Corbicula  existed  in  the  creek  only  at 
the  midstream  collecting  site.  In  March  1975 
there  were  no  Corbictda  at  the  upstream  site,  the 
midstream  population  included  some  larger  in- 
dividuals (>20mm)  and  the  downstream  site  was 
populated  by  many  small  animals  (<12mm).  By 
September  1976  both  the  mid-  and  downstream 
sites  included  animals  with  fairly  broad  ranges  of 
shell  lengths,  the  largest  still  occurring  at  the 


October  30, 1979 

Vol.94  (4) 

midstream  site.  No.  Corbicula  specimens  had  yet 
been  found  at  the  upstream  site. 

These  results  strongly  suggest  that  Corhiodn 
was  introduced  into  Saugahatchee  Creek  within 
one  kilometer  of,  and  within  a  few  months  of,  the 
screening  of  experimental  Corbicula  specimens  by 
Auburn  Fisheries  personnel.  These  results  docu- 
ment that  Corbicula  was  able  to  survive  and 
reproduce  in  a  stream  which,  apparently  because 
of  pollution,  is  incapable  of  sustaining  unionid 
populations.  So  far  as  the  spread  of  this  Cor- 
bicula population  is  concerned,  these  results  in- 
dicate that  an  easily  detectable  population  was 
established  approximately  ten  kilometers  down- 
stream from  the  apparent  site  of  introduction  in 
more  than  12,  but  less  than  28  months.  The  pop- 
ulation had  not  spread  one  kilometer  upstream  in 
approximately  48  months. 


The  factors  responsible  for  this  apparent 
unidirectional  colonization  pattern  are  presently 
unknown,  however,  stream  current  is  one  en- 
vironmental factor  which  could  produce  this  kind 
of  effect.  According  to  Sinclair  (1971)  the  North 
American  corbiculid  species  passes  through  a 
non -swimming,  pelagic,  veliger  larval  stage. 
When  these  larvae  are  released,  they  apparently 
cannot  swam  against  the  current  and  all  of  them 
are  carried  downstream.  The  unidirectional  effect 
of  current  alone,  therefore,  could  explain  the  lack 
of  upstream  colonization  in  Saugahatchee  Creek. 

The  unidirectional  effect  of  current  could  also 
explain  the  "unusual"  distribution  patterns  of  the 
Corbicula  populations  in  the  Uchee  Creek  system 
and  in  Mesilla  Valley.  In  both  cases,  if  Corbicula 
had  been  introduced  at  an  upstream  site,  the  re- 
mainder of  the  distribution  pattern  coincides  ex- 
actly with  the  areas  where  non-swimming  plank- 
tonic  larvae  would  be  carried  by  current.  In  the 
Uchee  Creek  system  current  would  adequately 
explain  why  no  Corbicula  specimens  were  found 
in  Uchee  Creek  proper  above  the  mouth  of  Little 
Uchee  Creek,  although  unionids  occur  in  both 
areas.  In  Mesilla  Valley  current  alone  could  pre- 
vent an  original  population  in  West  Drain  from 
spreading  into  any  tributary  that  maintained 
some  minimum  flow.  This  same  reasoning  could 
be  used  to  explain  why  Corbicula  does  not  occur 
in    other    east-central    Alabama    streams    even 

though  it  is  abundant  in  both  the  Tallapoosa  and 
Chattahoochee  rivers. 

Although  this  proposed  role  of  current  in  di- 
recting the  spread  of  Corbicula  populations  would 
seem  entirely  logical  and  expected,  I  have  found 
no  mention  of  it  in  the  extensive  American 
literature  concerning  Corbicula.  Other  ideas  have 
been  advanced,  however,  to  explain  the  oc- 
currence of  this  invading  organism  in  certain 
locations.  One  recently  proposed  hypothesis  is 
that  Corbicula  sometimes  becomes  established 
because  it  is  able  to  out-compete  the  native 
bivalves  in  areas  that  have  been  disturbed  by 
man  (Fuller  and  Imlay,  1976).  While  this 
hypothesis  may  fit  some  situations,  especially 
with  regard  to  sphaeriids  (e.g.  Gardner  et  al., 
1976),  it  does  not  seem  to  be  operating  in  the 
relatively  unaltered  Uchee  Creek  system  where 
unionids  and  Coribula  occur  together  in  large 
numbers.  In  addition,  the  information  presented 
in  the  abstract  by  Fuller  and  Imlay  appears  to 
support  this  "current  hypothesis"  better  than  the 
"competition  hypothesis"  they  propose. 

Corbicula  can  no  longer  be  considered  to  be  an 
oddity  only  worthy  of  a  casual  distributional 
note.  This  organism  is  now  a  dominant  member 
of  many  North  American  freshwater  faunas, 
often  much  more  abundant  than  any  other  mol- 
lusk.  Since  we  know  so  little  of  the  biology, 
ecology  or  taxonomy  of  this  newly-established 
species,  every  piece  of  factual  information  which 
appears  in  the  literature  can  only  serve  to  in- 
crease our  understanding  of  this  animal.  In  addi- 
tion to  the  theoretical  material  presented  in  this 
paper.  I  have  attempted  to  detail  the  present 
distribution  pattern  of  the  Corbicula  populations 
in  east-central  Alabama  as  completely  as  possi- 
ble. It  is  my  hope  that  future  workers  may  be 
able  to  use  these  data  in  various  ways  to  increase 
our  general  understanding  of  this  no-longer  alien 


Britton.  J.  C.  and  C.  E.  Murphy.  1977.  New  records  and  ecolog- 
ical notes  for  Cnrbicida  manilensis  in  Texas.  The  Nautilus 

Diaz.  R.  J.  1974.  Asiatic  Clam,  Corhiaila  nmnilensii  (Philip- 
pi),  in  the  tidal  James  River,  Virginia.  Chesapeake  Sci. 

Vol.94  (4) 

October  30, 1979 


Fuller.  S.  L  R  and  M.  J.  Imlay.  1976.  Spatial  comix;lilion 
between  Girbirula  manilensis  (Philippi).  the  Chinese  Clam 
(GirbiculiHae).  and  freshwater  mussels  (Unionidae)  in  the 
Waccamaw  River  basin  of  the  Carolinas  (Mollusca; 
Bivalvia).  .4.s.sor.  SmdheaMi'rn  Bill  Bull.  23:6(1. 

Fuller.  S.  L.  H.  and  C.  E.  Powell.  .Jr.  U)73.  Range  e.xtensions  of 
Ciirhicula  miiiiileiixis  (Philippi)  in  the  Atlantic  drainage  of 
the  United  States.  Tlie  Naidilii.^  87:.59. 

Gardner,  J.  A..  Jr.,  W.  R.  Woodall,  Jr..  A.  A.  Staats.  Jr.  and  J. 
F.  Napoli.  1976.  The  invasion  of  the  Asiatic  Clam  {Girhicula 
manilenxix  Philippi)  in  the  Altamaha  River,  Georgia.  Vie 

Hurd,  J.  C.  1971.  A  survey  of  the  mollusks  of  the  Chewacla 
and  Saugahatchee  creek  drainages  in  western  Lee  County, 
Alabama.  M.  S.  Tlirsis.  Auburn  Univ.  64  pp. 

.Jenkin.son.  J.  J.  1973.  Distribution  and  Z(joge(]graphy  of  the 
Unionidae  (Mollusca:  Bivalvia)  in  four  creek  systems  in 
east-central  Alabama.  M.  S.  Thesix.  Auburn  Univ.  96  pp. 

197.5.  The  Fall  Line  as  a  barrier  to  the  distribu- 
tion of  some  unionids  (Bivalvia:  Unionidae).  Amer. 
Mtduadoiiird  Union  Bull,  for  1974::30-31. 

Metcalf,  A.  L.  1966.  Corbicula  manUemdx  in  the  Mesilla 
Valley  of  Texas  ajid  New  Mexico.  Vi.e  Nautiiius  80:16-20. 

Sickel.  .1.  B.  1973.  A  new  record  of  Corbicula  manilenxi'; 
(Philippi)  in  the  Southern  Atlantic  Slope  Region  of  Georgia. 
77ir  Av,h/, 7 «.s- 87:11-12. 

Sinclair.  R.  M.  1971.  Annotated  bibliography  on  the  exotic 
bivalve  Corbiruln  in  North  America,  1900- 1971.  Stirkinnn 



Archie  L.  Jones 

1.37(1  S.W.  1 1th  Street 
Miami,  Floi-ida  33131 

In  the  spring  of  1962  I  found  a  group  of  snail 
hammocks  in  the  southern  Everglades  of  Florida 
that  had  never  before  been  explored  by  Liguus 
collectors.  One  of  these  supports  a  polvmorphic 
colony  of  Liguus  fnsciatus  (Miiller)  that  includes 
two  new  color  forms. 

In  Pilsbry's  (1946)  classification  of  Liguus 
fasciatus,  these  new  forms  would  be  placed  in  the 
subspecies  testudineus  Pilsbry.  Their  closest  rela- 
tionship is  vfith  the  form  nuitanem.  I  have  called 
these  two  forms,  or  morphs,  humesi  and  fmmp- 

Four  years  earlier  (19.58)  I  had  set  out  with  a 
friend  in  his  airboat  in  search  of  an  especially 
beautiful  form,  marrjfioratiis,  which  a  Seminole 
Indian,  Smallpox  Tommy,  had  shown  me.  We 
picked  up  Tommy  at  his  camp  three  miles  north 
of  the  Tamiami  Trail.  A  lack  of  communication 
between  the  Indian  and  us,  or  his  reluctance  to 
take   us  there,  prevented   us  from   finding  our 

'  Latinized  names  for  color  forms. ./» cm (i,  varieties,  or  aberra- 
tions are  useful  to  students  of  variation,  but  infrasub- 
specific  names,  proposed  after  1%().  have  no  nomenclatural 
standing,  and  hence  no  priority  over  properly  proposed  sjieci- 
fic  or  subspecific  names,  according  to  Articles  1  and  10b  of 
the  International  Code  Zool.  Nomen.  -  Editor. 

marmarntus.  The  group  of  hammocks  to  which  he 
took  us  contained  instead  a  new  fonn  of  the 
subspecies  testvdineus,  namely  evergiadesensis. 

The  deplorable  practice  by  collectors  of 
transplanting  the  Florida  tree  snail,  Liguiis 
/(isciatia^.  to  hammocks  already  populated  with 
other  Liguus  began  before  the  turn  of  the  last 
century  and  continues  to  this  day.  Collectors 
gathered  choice  specimens  of  this  magnificent 
snail  and  put  them  in  selected  hammocks  with 
the  e.xpectations  of  collecting  them  and  their  pro- 
geny tefore  some  other  collector  did.  In  1947  I  in- 
terviewed a  Mr.  Lincoln,  a  former  Florida  West 
Coast  shell  dealer.  He  was  then  in  his  late 
eighties  and  resided  in  a  rest  home  in  Ft.  Myers, 
Florida.  He  told  me  that  when  he  was  a  young 
man  he  transplanted  some  Liguus  from  Long 
Pine  Key  of  the  Lower  Everglades  to  Big  Pine 
Key  in  the  Lower  Florida  Keys.  Charles  Torrey 
Simpson  introduced  them  into  his  hammock  in 
Lemon  City  (North  Miami)  so  that  he  could  more 
easily  observe  and  study  them.  "In  my  bit  of 
forest,  into  which  I  have  carried  many  specimens 
from  elsewhere  -  -  -." 

A  great  fluriy  of  transplantation  occurred  im- 
mediatelv     before     the     establishment     of    the 


October  30, 1979 

Vol.  94  (4) 

Everglades  National  Park  in  1947.  Collectors 
rushed  to  the  then-to-be  Park  and  removed  some 
of  the  more  beautiful  varieties  and  relocated 
them  outside  the  Park  in  Pinecrest,  Collier  Coun- 
ty, the  East  Coast  Ridge  and  the  Florida  Keys. 
TTiey  hid  them  almost  anywhere  they  thought  the 
snails  would  not  be  found  by  other  collectors. 
Tliis  distribution  in  no  way  hurt  the  Park  col- 
onies but  the  cumulative  effect  of  all  the  in- 
troductions greatly  affected  the  gene  mix  of  once 
reasonably  stable  populations,  so  that  now  it 
would  be  next  to  impossible  to  work  out  the 
mystery  of  the  distribution  of  these  snails  in 
southern  Florida. 

Liginu^  feed  upon  the  minute  lichens,  fungi, 
sooty  molds  and  algae  that  grow  on  the  bark  and 
leaves  of  trees,  shrubs,  etc.  They  use  their  radulae 
to  scrape  these  foods  and  loose  particles  of  bark 
from  the  hammock  vegetation.  Newly  hatched 
snails  begin  feeding  at  the  bases  of  trees  and, 
during  periods  of  wet  weather,  work  their  way  to 
the  tops  of  the  trees,  feeding  as  they  go. 

In  the  descriptions  of  the  forms  that  follow,  I 
have  used  the  words  large,  medium  size  and  sub- 
solid  in  describing  the  size  and  solidity  of  shells. 
One  should  understand  that  the  size  and  solidity 
of  Liguus  shells  are  determined  to  a  lesser  degree 
by  heredity  and  to  a  greater  degree  by  the 
amount  and  quality  of  the  snail  food  found  in  a 
hammock.  It  follows,  therefore,  that  when  one 
describes  the  size  and  thickness  of  a  Liguiis  shell, 
one  describes  to  a  greater  degree  the  condition  of 
the  hammock  as  it  relates  to  Ligims  and  to  a 
lesser  degree  the  inherant  nature  of  the  shell 
itself.  For  example:  if  one  took,  say,  45  newly 
hatched  graphicus  from  one  small  colony,  divided 
them  equally  into  three  lots  and  put  one  lot  in  a 
hammock  with  a  maximum  amount  of  food  on 
the  lysiloma  and  Jamaica  dogwood  trees;  the  sec- 
ond group  in  an  identical  hammock  with  a  mini- 
mum of  food;  the  third  lot  in  a  hammock  forested 
principally  with  bustic  and  hackberry  with  opti- 
mum food,  one  would  get  three  very  different 
results.  If  one  were  to  describe  the  size  and 
solidity  of  each  group  at  the  end  of  the  third 
year  of  activity,  the  descriptions  would  be  ap- 
proximately as  follows: 

First  group  -  largesize(up  to70mm.),  solid; 

Second  group  -  small  size  (up  to  46  mm.),  thin; 

Third  group  -  large  size  (up  to  65  mm.),  thin. 

These  facts  were  not  understood  by  some  describ- 
ers  of  Liguus  and  it  has  caused  confusion  and  dif- 
ficulty in  subsequent  identifications  of  some 
forms  of  snails. 

Liguus  fasciatus  humesi,  new  form 

Figs.  .5, 6 
Description:  Shell  medium  size  (up  to  55  mm. 
in  length),  moderately  elongate,  subsolid;  texture 
lustrous  in  young  shells  to  dull  in  old  specimens; 
whorls  not  inflated,  slightly  convex;  columella 
sinuate  to  straight,  thin;  palatal  lip  smooth,  occa- 
sionally crenate  at  juncture  of  periostracal  green 
lines,  slightly  thickened  within. 

Color,  apex  pink;  columella  and  parietal  wall 
invariably  white  except  in  thin  shells  where  the 
color  of  the  shell  penetrates  the  very  thin  white 
callus  which  produces  a  slight  pinkish  effect; 
there  is  a  narrow  white  to  creamy  brown  sutural 
line;  the  third  whorl  is  light-pink  to  brown  and  is 
marked  with  a  few  brovm  axial  striae;  the  color 
of  the  fourth,  fifth,  sixth  and  last  whorls  is  dark- 
brown  to  almost  black,  broken  by  irregular 
yellowish  axial  stripes  (which  are  often  zigzag) 
and  blotches  that  often  extend  from  suture  to 
suture  on  the  fourth,  fifth  and  sixth  whorls  and 
from  suture  to  the  base  of  the  shell  on  the  last 
whorl;  there  is  a  narrow  yellowish  peripheral 
band  that  produces  a  dark  band,  broken  by 
yellow  axial  flames  and/or  blotches,  above  and 
below  the  periphery.  A  small  percentage  of  shells 
have  a  few  spiral  green  lines  above  and/or  below 
the  periphery. 

Type  material:  The  form  humeri  is  found  only 
in  an  isolated  group  of  hammocks  of  the  southern 
Everglades.  The  holotype  and  paratypes  were  col- 
lected March,  1962.  The  holotype  has  been  placed 
in  the  United  States  National  Museum,  Washing- 
ton, D.C.  It  is  a  four-year-old  shell;  length  46 
mm.,  width  23  mm.,  aperture  width  23  mm.,  dis- 
tance from  suture  to  base  of  shell  21.5  mm. 
Paratypes  have  been  placed  in  the  United  States 
National  Museum,  Washington,  D.C,  the 
Museum  of  Comparative  Zoology,  Harvard  Uni- 
vereity,  the  Academy  of  Natural  Sciences  of 
Philadelphia,  University  of  Florida,  Gainesville, 
and  the  Everglades  National  Park  Collection. 
Homestead,  Florida. 

Vol.  94  (4) 

October  30, 1979 


A  lot  of  129  shells,  collected  without  selection 
included  the  following  forms: 

castaneozonatus  U>1  78% 

cingidatus  11  9"/° 

humesi  9  7% 

fi-amptoni  5  4% 

'luteiis  3      2% 



The  color  form  humeri  differs  from  the  form 
castaneus  by  always  having  a  white  columella 
and  parietal  wall  and  by  the  absence  of  the  single 
or  double  peripheral  bands. 

In  1964  a  group  of  humesi  was  introduced  into 
a  hammock  containing  no  Liguus.  Since  then  I 
have  visited  this  hammock  scores  of  times  during 
the  last  15  years  and  have  not  seen  any  of  the 
other  forms  associated  with  it  in  its  native 

It  is  with  great  pleasure  that  I  name  this  shell 
for  one  who  has  played  a  significant  part  in  the 
history  of  Ligiuis  in  Florida,  Mr.  Ralph  Humes, 
now  of  Leesburg,  Florida,  intimate  friend,  de- 
lightful snailing  companion  and  dedicated  conser- 
vationist. He  donated  his  fine  large  Liguus  collec- 
tion to  the  Everglades  National  Park.  He  is  the 
originator  of  the  Park  Liguus  project  on  which  he 
collaborated  until  he  moved  from  Miami.  Mr. 
Humes  described  the  color  form  wintei  and  wrote 
a  history  oi  Liguus  collecting  in  Florida. 

Liguus  fasciatus  framptoni,  new  form 
Figs.  7, 8 

Dfscriptinn:  Shell  medium  size,  (up  to  .55  mm. 
in  length),  moderately  elongate,  subsolid;  texture 
lustrous  in  young  to  dull  in  old  shells;  whorls  not 
inflated,  slightly  convex  above  the  periphery;  col- 
umella sinuate  to  straight,  thin;  palatal  lip 
smooth,  occasionally  crenate  at  juncture  of 
periostracal  green  lines,  slightly  thickened 

Color:  apex  pink  with  a  minute  brown  spot  on 
its  summit:  columella  and  parietal  wall  in- 
variably pink  or  liver-colored;  there  is  a  narrow 
creamy  brown  sutural  line;  the  third  whorl  is 
creamy  brown,  sometimes  with  faint  narrow  light 
brown  axial  streaks;  the  color  of  the  fourth,  fifth, 
sixth  and  seventh  whorls  is  dark-brovm,  broken 
by  irregular  yellowish  axial  striae  (which  are 
often  zigzag)  and  blotches  that  often  extend  from 
suture  to  suture  on  the  fourth,  fifth  and  sixth 

whorls  and  from  the  suture  to  the  base  of  the 
shell  on  the  last  whorl;  there  is  a  narrow 
yellowish  peripheral  band  that  produces  a  dark 
band,  (sometimes  wanting  on  the  last  whorl) 
broken  by  yellow  axial  flames  and/or  blotches, 
above  and  below  the  periphery.  A  small  percent- 
age of  shells  have  a  few  faint  spiral  green  lines 
above  and/or  below  the  periphery.  A  brovra  or 
purplish  sinuating  line  borders  the  parietal  wall 
from  termination  of  the  suture  to  the  tip  of  the 
columella.  It  is  a  parallel  form  to  humesi,  differ- 
ing only  in  the  light -brown  coloration,  the  pink 
or  liver -colored  columella  and  parietal  wall  and 
the  pink  apex  with  the  minute  brown  spot  at  the 

Type  material:  This  color  form  is  found  wath 
humesi,  castaneozonatus,  cingulatus  and  luteus  in 
an  isolated  group  of  hammocks  of  the  southern 
Everglades  referred  to  above  in  the  description  of 
humesi.  The  holotype,  a  three-year-old  shell,  has 
been  placed  in  the  United  States  National  Mu- 
seum, Washington,  D.C.  Its  length  is  47  mm., 
width  23  mm.,  aperture  width  12  mm.,  distance 
from  suture  to  base  of  shell  21  mm.  Paratypes 
have  been  placed  in  the  United  States  National 
Museum,  Washington,  D.C,  the  Museum  of  Com- 
parative Zoology,  Harvard  University,  the 
Academy  of  Natural  Sciences  of  Philadelphia, 
University  of  Florida,  Gainesville,  and  the 
Everglades  National  Park  Collection,  Homestead, 

The  offspring  of  a  number  of  framptoni  in- 
troduced several  years  ago  into  a  hammock 
devoid  of  Liguus  were  predominately  framptoni, 
some  humesi,  luteus  and  very  rarely  castaneo- 

I  have  named  this  form  in  honor  of  Henry  G. 
Frampton  (1902  -  1966),  one  of  the  early  modern 
collectors  of  Florida  Liguus,  who  contributed  to 
the  literature  by  describing  the  forms  splendidus, 
fuscoflammellus  and  clenchi.  His  widow, 
Theodosia,  presented  his  fine,  large  Liguus  collec- 
tion to  the  Museum  of  Comparative  Zoology,  Har- 
vard University. 

Liguus  fasciatus  evergladesensis,  new  form 

Figs.  1,  2 
De.'icription:  Shell  medium  size,  moderately  in- 
flated, subsolid,  texture  matt  or  without  much 
gloss;  whorls  convex,  last  whorl  well  rounded; 


October  30, 1979 

Vol.  94  (4) 

FIGS.  1-12.  Ncir  aiUir  forma  i//' Liguus  fascial  as  (MHJIri)  fraiii  tin  Hunihi  Erny(nd(x.  Aiicrho-nl  ririrs  (ire  hulnlftixs.  dfD-xal 
itiews  are  paralj/pes.  1,  2,  evergladesensis.  3,  4,  margaretae.  .'5,  6,  luimesi.  7.  8.  fiamptoni.  9,  10.  keiiiiethi.  11.  12,  beardi.  .4// 
formae  nnvae./(;HP.s.  1.979. 

Vol.i»4  (1) 

October  30. 1979 


sutures  not  ver>'  deep,  well  shouldered;  columella 
usually  thin,  straight  and  simple,  occasionally 
slightly  sinuated;  palatal  lip  smooth,  slightly 
crenate  at  juncture  of  periostracal  green  lines, 
slightly  thickened  within. 

Gill))-:  apex,  columella  and  parietal  wall  in- 
variably pink.  Ground  color  is  light-yellow.  Tlie 
antepenult  whorl  is  marked  by  a  broad  smoky 
lavender  band  broken  by  yellow  vertical  flames 
or  blotches.  Above  and  below  this  band  are  nar- 
row i-ufescent  bands.  On  the  penultimate  and 
body  whorls  the  broad  band  degenerates  into 
alternating  vertical  smoky  lavender  and  light- 
yellow  flames.  The  two  narrow  bands  become  a 
series  of  comma-like  blotches.  The  yellow  ground 
color  predominates.  On  the  body  whorl,  the  ver- 
tical flames  are  broken  at  the  periphery'  by  a 
very  light-yellow  band  and/or  a  lavender  line. 
The  columella  is  bordered  by  a  narrow  pink  line. 
There  is  a  narrow  reddish  brown  basal  line  which 
is  often  reduced  to  a  series  of  blotches.  Almost  all 
shells  have  from  one  to  five  spiral  green  lines 
ab(3ve  the  periphery  and  from  one  to  four  below. 

Tifpe  material:  The  type  locality  is  one  of  a 
group  of  four  or  five  hammocks  about  one  mile 
west  of  Canal  Levee  28  about  six  miles  north  of 
the  40-Mile  Bend  of  the  Tamiami  Trail.  The 
holotype  has  been  placed  in  the  United  States 
National  Museum,  Washington,  D.C.  It  is  a 
three-year-old  shell:  length  48  mm.,  width  25 
mm.,  aperture  width  14  mm.,  distance  from 
suture  to  base  of  shell  23  mm.  Paratypes  have 
been  placed  in  the  United  States  National 
Museum.  Museum  of  Comparative  Zoology,  Har- 
vard University,  the  Academy  of  Natural 
Sciences  of  Philadelphia,  University  of  Florida  at 
Gainesville  and  the  Everglades  National  Park 
Collection,  Homestead,  Florida. 

Comments:  Form  erergladesensis.  in  its  first 
year  superficially  resembles  castanetis  but  in 
later  growth  the  juxtasutural  bands  are  absent  or 
reduced  to  a  series  of  blotches.  The  columella  and 
parietal  wall  are  invariably  pink  whereas  in  most 
castaneiis  they  are  white.  It  is  unique  among 
Pinecrest  and  Collier  County  subspecies 
testudineus,  being  the  only  form  having  a  full 
pink  tip.  I  doubt  if  there  is  any  close  genetic  rela- 
tionship between  evergladesenfsis  and  castanem. 
Over  50  miles  separate  the  two  forms.  The  closest 
hammocks  containing  castaneus  are  those  of  the 

L)ng  Pine  Key  area  near  Homestead.  The  form 
evergladesensis  is  found  with  livingntoni,  the 
predominant  form,  and  with  the  form  floridanus. 
It  is  interesting  that  while  they  are  found  in  a 
pol^Tnorphic  population  they  breed  true  to  form 
when  isolated.  Such  populations  introduced  in 
two  s(juthern  Everglades  hammocks  in  1961  have 
never  produced  any  other  forms. 

Liguus  fasciatus  margaretae,  new  form 
Figs.  .3, 4 

Description:  Shell  large  (to  64  mm.  in  length), 
elongate;  texture  subsolid  with  a  sheen  but  ap- 
pears dull;  body  whorl  convex,  well-shouldered; 
penultimate  whorl  convex;  the  antepenult,  fourth 
and  third  whorls  flat;  columella  straight,  not 
thin,  slightly  twisted,  occasionally  obliquely  trun- 
cated; palatal  lip  slightly  thickened  within, 
usually  crenate  at  juncture  of  periostracal  green 
lines  which  are  numerous  and  always  present. 

C(ilo)"  columella  and  first  two  or  three  whorls 
of  spire  are  white.  There  is  a  narrow  supra- 
sutural  creamy  yellow  band  and  a  subsutural 
mahogany-colored  line.  The  fourth  whorl  is 
ivoiy-white  broken  by  reddish  brown  subsutural 
spots  that  often  develop  into  vertical  striae  that 
extend  downward  almost  to  the  suture.  The  fifth, 
or  antepenult  whorl,  has  a  broad  bluish  gray 
band  broken  by  light-tan  vertical  flares  that  in- 
creasingly diffuse  on  the  penultimate  and  body 
whorls  and  on  the  body  whorl  are  overlaid  with  a 
blue-green  wash  above  the  reddish  mahogany 
peripheral  line  and  a  wide  darker  green  wash 
below  the  light-tan  narrow  band  that  lies  im- 
mediately below  the  peripheral  line.  There  is 
often  a  baby-blue  line  immediately  above  the 
))eripheral  line.  An  orange  basal  band  borders  the 
columella  and  it  is  bordered  by  a  much  darker 
band  that  extends  from  the  base  of  the  shell  to 
approximately  two-thirds  the  distance  to  the 

Type  material:  Tlie  type  locality  is  a  small 
hammock  of  the  southern  Everglades.  The  holo- 
type is  a  mature,  three-year-old  shell,  length 
.54.5  mm.,  width  26  mm.,  aperture  width  13  mm., 
distance  from  suture  to  base  of  shell  22.5  mm.  It 
has  been  place  in  the  United  States  National 
Museum.  Washington.  D.C.  Paratypes  were  also 
placed  there  and  in  the  collections  of  the 
Everglades  National   Park,   Homestead.  Florida. 


October  30. 1979 

Vol.  94  (4) 

Museum  of  Comparative  Zoology,  Harvard  Uni- 
versity, Academy  of  Natural  Sciences  of  Phila- 
delphia and  the  University  of  Florida  at  Gaines- 

Comments:  TTiis  race  of  snails  descended  from 
five  snails  that  appeared  in  a  hammock  in  which 
I  had  placed  together  lucidovarim  from  Pinecrest 
Hammock  No.  11  and  clenchi  from  Pinecrest 
Hammock  No.  88.  One  of  these  shells  had  a  so- 
called  "jewel  tip",  or  apex  of  pinkish  brown.  This 
population  produced  the  two  above-mentioned 
forms,  lossmanicus,  many  intermediates  and  the 
five  ancestors  of  margaretae. 

The  five  snails  were  transferred  to  another 
hammock  which  had  no  snails.  Two  years  later  I 
returned  and  saw  about  15  newly  hatched  snails 
(all  of  the  white-tipped  form),  three  white-tipped 
parents  and  the  dead  jewel-tipped  shell.  If  this 
jewel-tipped  snail  died  before  it  mated  it  could 
account  for  the  white-tipped  offspring. 

One  would  expect  to  find  the  polymorphism  of 
the  first  hammock  to  show  itself  in  the  snail 
population  of  the  second  hammock  but  this  has 
not  occurred.  Since  the  introduction  in  July,  1969 
all  offspring  have  been  margaretae. 

The  distinguishing  characteristics  of 
margaretae  are  the  light  blue-green  wash  over 
the  body  whorl  and  the  spire  pattern  of  lucida- 
varl'm.  In  recently  collected  shells  the  wash  ap- 
pears to  be  more  blue  than  green  but  as  the  colors 
fade  green  predominates. 

I  name  this  shell  for  my  wife  whose  patience 
and  understanding  made  it  possible  for  me  to 
spend  many  thousands  of  hours  in  the  field  these 
45  years  since  I  first  began  snailing  in  1934. 

Liguus  fasciatus  beardi,  new  form 
Figs.  11, 12 
Description:  Shell  similar  to  that  of 
margaretae,  except  for  color  and  pattern.  First 
whorl  of  spire  pink,  faintly  tinged  with  brovwi  at 
the  summit.  Next  two  or  three  whorls  ivory-white 
or  white,  sometimes  flecked  with  ochre.  There  are 
supra  and  subsutural  light-brown  lines  which  are 
darker,  heavier  and  broken  on  the  antepenult 
whorl.  On  the  penultimate  whorl  this  line  some- 
times appears  as  brownish  spots.  The  overall  m/- 
or  of  the  shell  is  grayish  brown  wash,  broken  at 
the  periphery  by  a  wide,  lighter  colored  band 
which  is  dissected  by  a  heavy,  browTi  or  maho- 

gany line.  There  are  usually  four  or  five  green 
lines  above  and  about  three  or  four  brownish 
green  ones  below  the  peripher\'.  The  columella  is 
white  or  nearly  so.  The  parietal  wall  is  light- 
purple.  There  is  a  brownish  purple  line  bordering 
the  parietal  wall  which  extends  from  the  suture 
to  the  tip  of  the  columella.  Bordering  this  line  at 
the  base  of  the  shell  is  a  lighter  colored  band 
sometimes  bordered  by  a  darker  one. 

Tifpe  material:  The  type  locality  is  a  small 
hammock  of  the  southern  Everglades  near  the 
t.\i)e  locality  of  margaretae.  The  holot\T3e  is  an 
adult  three-year-old  shell:  length  54  mm.,  width 
26  mm.,  aperture  width  14  mm.,  distance  from 
suture  to  base  of  shell  24  mm.  The  holotype  has 
been  placed  in  the  United  States  National 
Museum,  Washington,  D.C.  Paratypes  have  been 
placed  in  the  United  States  National  Museum, 
the  Everglades  National  Park  Collection, 
Homestead,  Florida,  Museum  of  Comparative 
Zoology,  Harvard  University,  Academy  of 
Natural  Sciences  of  Philadelphia  and  the  Univer- 
sity of  Florida,  Gainesville. 

Comments:  There  is  almost  a  total  lack  of  ver- 
tical markings  of  any  sort,  except  as  described 
above.  Occasionally  a  shell  will  have  a  trace  of 
the  blue-green  wash  of  margaretae  on  the  body 

It  gives  me  much  pleasure  to  name  this  shell 
for  Dan  Beard,  first  superintendent  of  the 
Everglades  National  Park,  whose  foresight  and 
encouragement  made  possible  the  introduction  of 
rare  and  beautiful  forms  of  Lignus  into  the  Park 
where,  hopefully,  they  will  be  saved  for  future 
generations  of  scientists  to  study  and  for  Park 
visitors  to  observe  and  enjoy. 

Liguus  fasciatus  kennethi,  newform 

Fi^s.  9.1(1 

Description:  Shell  large  (to  62  mm.),  moderate- 
ly elongate,  subsolid  to  solid,  somewhat  lustrous 
to  dull;  whorls  7-7':,  convex;  columella  heavy, 
straight  but  slightly  twisted,  obliquely  truncated. 

Color:  first  three  whorls  of  the  apex  and  col- 
umella ivory-white,  parietal  wall  veiy  light-flesh 
color.  The  ground  color  of  the  body  whorl  is 
yellow  with  an  overlay  of  blotches,  smears  and 
v(>rtical  strijies  of  burnt  umber  and  umber  which 
fade  with  time  to  yellow-ochre.  There  is  a  very 
narrow  yellowish  cream  subsutural   line  and  a 

Vol.  94  (4) 

October  30, 1979 


narrow  (1  -  2  mm.)  peripheral  band  of  the  same 
color,  sometimes  bordered  above  by  a  lavender 
line.  As  the  colors  fade,  each  year's  markings 
become  lighter  so  that  in  some  old  shells  the 
whorls  above  the  body  whorl  are  almost  white.  A 
few  specimens  show  on  the  body  whorls  some 
spiral  bandings  as  in  the  form  floridanus. 
Periostracal  green  lines  seldom  present  and  few 
in  number.  Grovrth-rest  varices  slightly  expanded. 

Type  material:  The  type  locality  is  a  small 
hammock  of  the  southern  Everglades.  The  holo- 
type  is  a  four-year-old  shell,  length  59  mm.,  width 
28  mm.,  aperture  width  15.5  mm.,  distance  from 
suture  to  base  of  shell  26  mm.  The  holotype 
has  been  placed  in  the  collection  of  the  United 
States  National  Museum,  Washington,  D.C. 
Paratypes  have  been  placed  in  the  United  States 
National  Museum,  the  Museum  of  Comparative 
Zoology,  Harvard  University,  the  Academy  of 
Natural  Sciences  of  Philadelphia,  University  of 
Florida,  Gainesville,  and  the  Everglades  National 
Park  Collection,  Homestead,  Florida. 

Comments:  The  progenitors  of  kennethi  first 
appeared  in  Pinecrest  Hammock  No.  13  into 
which  Mr.  Erwin  C.  Winte  had  comingled  some 
introduced  Liguus  with  the  native  population. 
Unfortunately,   no    records   were   kept    and    in- 

formation as  to  the  identity  of  the  forms  in- 
troduced is  uncertain.  Mr.  Winte  and  I  isolated 
five  snails  of  this  new  form  in  a  barren  ham- 
mock. Later  most  of  the  progeny  were  transferred 
to  another  hammock.  Since  then,  the  two  colonies 
have  remained  monomorphic.  This  phenomenon, 
plus  the  fact  that  kennethi  shows  no  similarity  to 
any  of  the  forms  of  the  original  population  leaves 
its  geneology  uncertain.  Its  overall  shape  and  ap- 
pearance indicate  only  mainland  forms  were  in- 
volved but  its  somewhat  glossy  appearance  in  five 
and  six-year-old  specimens  suggests  the  influence 
of  a  Florida  Keys  ancestor. 

I  name  this  snail  for  my  son  whose  help  in  the 
exploration  for  suitable  hammocks,  collecting 
Ligims  material  and  establishing  it  in  the 
Everglades  National  Park  contributed  substan- 
tially to  the  success  of  the  Park  Liguus  Project. 


FVampton.    Henry    G.     19.32.    Pr<ic.    Biological    Society    of 

Washtngton,  DC.  45:55-57. 
Humes.  Ralph  H.  19.54.  Go-sCropirfm  1(2):10. 

1965.  Tequesta,  No.  25:67-82. 

Pilsbry,  Henry  A.    1946,   Academy  of  Natural  Sciences 

Philadelphia.  Monographs  No.  3. 2(part  1):37-102. 
Simpson,    Charles    T.    1929.    Proc.    United   States 
Museum  73(Art.  20):l-44,pls.l-4 





R.  Tucker  Abbott 

American  Malacologists,  Inc. 
Melbourne,  Rorida  32901 

C.  John  Finlay 

and  116  Tanglewood  Lane 

Newark,  Delaware  19711 

Despite  the  fact  that  the  taxonomy  of  the  fami- 
ly Muricidae  has  recently  suffered  under  the 
hands  of  various  conflicting  interpretations  (E.  H. 
Vokes,  1971,  Radwin  and  D'Attilio,  1976;  Wagner 
and  Abbott,  1978),  new,  apparently  valid,  taxa 
continue  to  come  to  light  (Emerson  and  D'Attilio, 
1979).  Contributing  to  our  knowledge  of  marine 
mollusks  is  a  corps  of  enthusiastic  SCUBA  divers 
and  ardent  private  shell  collectors.  An  outstan- 
ding example  are  the  collecting  efforts  of  Mr. 
Dieter  Cosman  of  Long  Island,  New  York,  who 
has  personally  collected  and  documented  numer- 

ous outstanding  conchological  discoveries  in  the 
tropical  Western  Hemisphere. 

Among  Mr.  Cosman 's  unusual  discoveries  is  a 
colony  of  Chicoreus  muricid  snails  from  Jamaica 
representing  a  species  which  evidently  has  not 
been  given  a  valid,  scientific  name.  We  take  great 
pleasure  in  naming  this  new  species  after  him. 

Chicoreus  cosmani  new  species 

(Figs.  1-9) 
Description:   Shell   moderate   in   size   for   the 
genus,  attaining  a  length  of  79  mm.,  trigonally 


October  30. 1979 

Vol.  9-1  (1) 

F^KiS.  1-9.  Chiaireus  cosmani  Ahhntt  and  Finlay.  new  xpcriem.  Orhn  Rios.  Jiimmcn.  5,  in  the  center  is  the  halatjipe.  7!)  mtn.  in 
Icmjth.  the  other Jiyurex  are  ixirntifftesfnim  the  name  locality.  Collected  by  Dieter  Coxman.  Maivh  1967. 

Vol.  91  (1) 

October  30. 1979 


fusiform  in  shape.  Spire  acute,  with  an  angle  of 
35°  to  40°,  and  about  45  percent  of  the  entire 
length  of  the  shell.  Nuclear  whorls  1  1/2  glossy- 
smooth,  convex,  small  but  bulbous,  whitish  to  tan, 
and  with  a  well-indented  suture,  followed  by  S  or 
9  convex,  well-sculptured,  p(_)st -nuclear  whorls. 
First  few  whorls  with  a  cancellate  sculpture  be- 
tween the  varices.  Suture  finely  impressed  and 
slightly  wavy.  Aperture  relatively  small,  about 
one-fourth  the  length  of  the  entire  shell,  and  with 
the  peristome  entire.  Parietal  wall  glossy,  slightly 
raised,  and  tinted  with  yellow,  orange-brown  or 
pinkish.  Outer  lip  scalloped  and  bearing  10  to  12 
minute,  raised,  white  denticles.  Siphonal  canal 
moderately  broad,  nearly  sealed,  and  slightly 
recurved  dorsally  and  to  the  right  at  the  distal 
end.  Former  siphonal  canal  half  as  large,  tube- 
like, recurved  to  the  left,  and  bearing  on  its  sur- 
face a  half-dozen  axial,  irregular,  small  cords. 
Last  (and  earlier)  whorls  with  three  varices, 
originating  just  behind  the  varix  above  it  on  the 
previous  whoi'l.  Each  varix  in  the  body  whorl 
bears  8  short,  bi-  or  tri-furcate,  scaly,  partially 
(or  rarely  entirely)  closed  fronds.  Tliree  of  these 
fronds  are  on  the  right  side  of  the  siphonal  canal. 
In  the  early  whorls  the  top  frond  is  usally  twice 
the  size  of  those  below.  Intervarical  sculptui'e 
consists  of  4,  I'arely  3,  even-sized  axial,  low  cords 
whicli  ai'e  crossed  by  numerous  finer,  spiral 
cords,  thus  foi-ming  a  pattern  of  low,  rounded 
beads,  oi-  tiny  knobs,  all  about  the  same  size.  Col- 
or of  shell  varies  from  a  uniform  brownish 
orange  to  a  pale  yellow  orange,  rarely  white.  In- 
terior of  aperture  white,  with  an  orange-stained 
columella.  Operculum  chitinous,  light-brown,  oval, 
unguiculate.  with  fine,  scaly  concent ic  giviwth 

Measurements  (mm) 



(tvith  ifpines) 


no.  whorls 

holot)^*.  fig.  5. 
parat>'pe,fig.  7. 
parat.vpe,  fig.  6. 
paratype,  fig.  3. 
parat>T)e.fig.  2. 

Type  Inaditij:  on  pilings  at  the  Reynolds  Baux- 
ite dock,  Ocho  Rios,  north  side  of  Jamaica.  10  to 
15  feet.  March  1967.  Dieter  Cosman,  collector. 

Tapes:  Tlie  holotyi)e  (Fig.  5)  has  been  de]>)sited 
in  the  U.  S.  National  Mu.seum  no.  78-332.3.  Para- 

FIGS.  10,  11.  Chicoreus  species  from  Curaecu)  resemUing 
cosmani.  29  mm.  in  length.  Collected  by  Henk  Bielderman, 
197-1  CiDistance  Boone  collection  Photos  courtesy  of  Emily 

types  are  in  the  collection  of  Dieter  Cosman,  C. 
•John  Finlay,  the  Academy  of  Natural  Sciences  of 
Philadelphia,  the  Amer.  Mus.  Nat.  Hist.,  .Jerome 
Bijui',  and  the  Delaware  Museum  of  Natural 
History.  Specimens  have  been  reported  as  "very 
uncommon  in  about  .35  feet  at  the  Bogue  Islands, 
Discovery  Bay,  Orange  Bay  and  Bull  Bay  (ajuth 
coast),  .Jamaica,  in  water  as  deep  as  60  feet  by 
Michael  Humfrey  (1975,  p.  131,  pi.  1.5,  figs,  10, 
10a).  We  have  not  seen  these  specimens.  One 
paratype  (Acad.  Nat.  Sci.  Philadelphia  no.  3.5419) 
worn  in  condition,  was  collected  by  Robert  Swift 
in  St.  Thomas,  Virgin  Islands,  in  the  1860's. 

Remarks:  The  Chicoreus  complex  in  the  Carib- 
bean is  complicated  by  the  existence  of  a  number 
of  species,  subspecies  and  local,  isolated  forms,  so 
that  the  present  status  of  our  knowledge  is  still 
far  from  complete.  We  believe  that  C.  cosmani  is 
a  valid  species,  closely  related  to  C.  dilectus  (A. 
Adams,  1855),  brevifrons  (Lamarck,  1822),  spec- 
trum (Reeve,  1855)  and  flurifer  (Reeve,  1845).  It 
differs  markedly  from  those  other  species  in  hav- 
ing 3  or  4  axial  rows  of  rounded  beads  between 
the  varices,  somewhat  reminiscent  of  the  sculp- 
turing seen  in  Bursa  pileare  (Linnaeus).  The 
other  species  usually  have  one  large  and  one  or 
two  smaller  knobs  on  the  shoulder  of  the  whorl. 
In  breinfrons  and  mergus  E.  Vokes,  1974,  the 
spire  is  much  lower,  the  shell  more  quadrate,  and 


October  30, 1979 

Vol.94  (4) 

the  upper  spine  on  the  varix  much  larger  and 
longer  than  those  below.  Closest  to  cosmani  is  the 
specimen  from  Curacao  illustrated  and  identified 
by  Ruth  Fair  (1976,  pi.  6,  figs.  73,  73a)  as 
Chicoreus  pudoricolor  (Reeve,  1845).  This  may  be 
a  darkly  striped,  less  beaded  form  of  cosmani. 
The  type  and  only  known  specimen  of  pudoricolor 
was  returned  to  Denmark  by  Reeve,  and  has  not 
been  subsequently  relocated.  The  original  illustra- 
tion and  description  suggests  a  species  more  like 
corrwgatus  (Sowerby,  1841)  or  a  young  spectrum. 
We  consider  pudoricolor  a  species  inquirenda. 
The  Indo-Pacific  counterpart  of  cosmani  is 
akritos  Radwin  and  D'Attilio,  1976,  from  north- 
ern Australia. 

We  would  like  to  thank  Dieter  Cosman  for  his 

generosity  in  contributing  the  holotype  to  the 
U.  S.  National  Museum,  Smithsonian  Institution, 

and  Jerry  Harasewych  for  his  excellent  photo- 
graphy, and  Emily  E.  Yokes,  Constance  E.  Boone 
and  the  Walter  N.  Carpenters  for  information 
and  the  loan  of  related  species. 


E>nerson,  W.  K.  and  A.  D'Attilio,  1979.  Six  New  Living 
Species  of  Muricacean  Gastropods.  The  Nautilus  93(1):1-10. 

Fair,  Ruth  H.  1976.  The  Murex  Book:  An  Illustrated 
Catalogue  of  Recent  Muricidae.  Honolulu,  Hawaii.  138  pp., 
363  figs. 

Humfrey.  Michael.  1975.  Sea  Shells  of  the  West  Indies. 
Taplinger  Pub.  Co..  NY.  3.51  pp..  32  pis. 

Radwin,  George  E.  and  Anthony  D'Attilio.  1976.  Murex  Shells 
of  the  World.  An  Rlustraied  Guide  to  the  Muricidae.  Stan- 
ford Univ.  Press.  284 pp.,  32 pis. 

■Vokes,  Emily  H.  1971.  Catalogue  of  the  Genus  Murex  Linne; 
Muricinae, Ocenebrinae.  Bu/i  Amer.  Paleont.  61(268):1-141. 

Wagner,  R.  J.  L.  and  R.  T.  Abbott.  1978.  Standard  Catalog  of 
Shells  Supplement  I  pp.  13-801  -  13-810.  American 
Malacologists,  Melbourne,  FL. 



Susan  B.  Gallagher 

12250  6th  Street  East 
Treasure  Island.  FL  33706 



George  K.  Reid 

Eckerd  College 
Petersburg,  FL  33733 

Seasonal  changes  in  population  density  and  size  class  distribution  reflect  the 
seasonal  nature  of  reproduction  in  Littorina  angulifera  in  the  Tampa  Bay.  Florida, 
area  The  zonation  pattern  of  adult  snails  and  juveniles  is  described.  Both  extreme- 
ly high  tides  and  a  Gymnodinium  breve  "Red  Tide"  bloom  reduced  the  population 
density.  The  Gymnodinium  bloom  killed  new  recruits  differentially  and  had  a 
long-lasting  effect  on  the  population  density.  The  data  show  that  most  new 
recmits  reach  spawning  size  9  to  10  months  after  metamorphosis.  Most  adults  do 
not  survive  to  spawn  after  two  years,  as  there  is  an  approximate  70  percent  yearly 

This  is  our  second  report  dealing  with  Lit- 
torina angulifera  (Lamarck)  in  the  Tampa  Bay 

area.  The  first  dealt  with  reproductive  behavior 
and  early  development  (Gallagher  and  Reid, 
1974);  this  report  characterizes  the  composition 

Vol.  94  (4) 

October  30, 1979 


and  zonation  of  a  Tampa  Bay  population  of  L. 
angulifera  and  describes  seasonal  changes  in  it 
from  October  1971  through  May  1975.  In  addition, 
two  unusual  natural  environmental  stresses  oc- 
curred during  the  course  of  the  study.  Excessively 
high  tides  three  to  five  feet  above  normal  (Simon, 
1974),  accompanied  Hurricane  Agnes  in  June 
1972  and  an  extensive  outbreak  of  "red  tide" 
caused  by  blooms  of  the  dinoflagellate,  Gipn- 
rmdinium  breve,  in  the  winter  and  spring  1974. 
Effects  of  these  events  are  described  and  resul- 
tant changes  compared  with  those  in  non-stress 

Although  various  Ldttorina  species  have  been 
investigated  extensively,  only  Borkowski  (1974) 
has  studied  seasonal  population  changes  and 
growth  in  groups  of  littorines  over  a  period  of 
several  years.  Palant  and  Fishelson  (1968) 
reported  on  the  reproductive  cycles  and  ecology 
of  L.  punctata  and  L.  neritoides  in  the  Mediterra- 
nean Sea,  but  seasonal  changes  in  population 
density  and  size  distribution  were  not  considered. 
Lenderking  (1954),  in  her  work  on  the  biology  of 
L.  angulifera  in  the  Miami,  Florida,  area  studied 
growth,  reproduction  and  size  distribution  pat- 
terns, but  data  were  sparse  on  small  snails 
because  they  were  difficult  to  detect  in  the 
mangrove  habitat  in  which  she  worked.  Popula- 
tion density  studies  were  not  done.  Hayes  (1929) 

and  Moore  (1937)  investigated  shell  growth  in  L. 
littorea;  Moore  also  reported  on  spawning,  length 
of  life  and  mortality  in  this  snail.  Bingham  (1972) 
investigated  the  growth  and  ecology  of  L.  irrorata 
but  none  of  these  studies  investigated  seasonal 
changes  in  snail  populations  as  reported  here. 
Much  has  been  done  also  on  zonation  patterns  of 
littorines  by  Smith  and  Newell  (1954),  Evans 
(1965),  Bock  and  Johnson  (1967)  and  Chow  (1975) 
among  others.  In  addition  to  studies  involving  on- 
ly littorines,  others  have  investigated  desiccation, 
temperature  and  salinity  changes,  and  behavior 
patterns  in  relation  to  observed  zonation  patterns 
of  intertidal  animals  generally  (Broekhuysen, 
1939;  Kensler,  1967;  Markel,  1971;  and  Vermeij, 
1972).  There  are  very  few  investigations  en- 
compassing the  complete  life  history  of  pro- 
sobranch  mollusks  done  in  such  a  way  that  life 
cycles  of  the  species  can  be  illustrated  from  one 
spawning  season  to  the  next  and  so  related  to 
seasonal  changes  in  population  density  and  size 
distribution  (however,  see  Frank,  1965).  Results 
reported  here,  coupled  with  those  obtained  in  a 
previous  study  on  reproductive  behavior  (Gal- 
lagher and  Reid,  1974)  depict  events  in  the  life 
history  of  this  snail,  but  we  do  not  attempt  to 
analyze  the  factors,  whether  physiological  or  en- 
vironmental which  may  be  causal  in  these  events. 



^    140 




100- - 



i  ^•^■ 

\       t^ 

Hurricane  Agnes 

.-^  Area  A 
— -o  Areo  B 

Q  z  o 


1971  1972  1973  1974  I97S 

FIG.  1.  Fluftuations  }n  population  density  o/Littorina  angulifera /rom  October  1971  through  May  1975  in  two  areas  of  seaivall. 
Except  for  the  large  differences  in  recruitment  in  the  fall  of  1971  the  populations  densities  in  the  two  areas  were  similar. 


October  30. 1979 

Vol.  91  (1) 

There  is  some  question  regarding  the  tax- 
onoinic  status  of  this  snail.  Rosewater  (1963) 
stated  that  it  was  a  subspecies  of  the  Indo-Pacific 
snail  Littorina  scahra  and  so  should  be  called  L. 
Hcuhra  (DH/nlifpra.  It  was  so  called  in  our  first 
report  (Oallagher  and  Reid,  1974).  However. 
Bandel  (1974),  in  his  study  of  Atlantic  Lit- 
torinidae.  more  recently  stated  that  radular  dif- 
ferences between  the  two  are  such  that  they 
should  be  considered  separate  species.  Because  of 
this  and  because  Abbott  (1974)  also  considers 
these  two  as  separate  species,  this  animal  is  so 
considered  in  this  report.  Until  this  taxonomic 
problem  is  cleared  up  we  believe  it  less  confusing 
to  refer  to  the  organism  as  L.  an(julifera  since  it 
is  so  designated  in  most  of  the  literature. 

Most  of  the  animals  in  this  study  occupied  a 
vertical  concrete  seawall  bordering  a  canal  in 
Boca  Ciega  Bay  immediately  south  of  John's  Pass 
in  Treasure  Island,  Florida  (27°47'N,  82°47'W). 
The  seawall  habitat  was  chosen  because  of  the 
ease  of  observing  and  counting  animals  on  it  in 

contrast  to  attempts  to  study  these  animals  in  a 
5pa/■^^«« -mangrove  community.  Although 
previous  work  (Gallagher  and  Reid,  1974)  in- 
dicated that  the  seawall  is  a  less  favorable 
habitat  than  the  Spart/na-mangrove  area,  obser- 
vations indicated  that  the  same  pattern  of 
reci'uitment  and  zonation  occurred  in  both  places. 
Therefore,  we  felt  results  of  this  study  would  ap- 
ply generally  to  the  species  in  this  area. 

The  seawall  is  composed  of  upright  concrete  slabs 
130-11(1  cm  high  and  120  cm  wide;  the  canal  bot- 
tom is  composed  of  soft  mud  and  oyster  bar.  Dur- 
ing the  study  the  lowermost  30-40  cm  of  seawall 
were  encrusted  with  oysters  (Crassostrea 
riiyinicn)  and  barnacles  (Biluitn.s  lunphitrite. 
('hfh<tni(du.s  spp.).  Tlie  isopod,  Ligid  sp.  was  one 
of  the  most  conspicuous  animals  in  the  habitat. 
An  intertidal  zone  approximately  9  m  wide  ex- 
tended horizontally  from  the  base  of  the  seawall 
since  this  much  of  the  canal  bottom  was  exposed 
at  low  spring  tides.  In  1971,  at  the  beginning  of 
the  study,  both  L.  anguUfem  and  L.  irromta 
were  present  on  the  seawall,  but  during  that  year 
the  numbers  of  the  latter  species  gradually 
declined  so   that   by   1972  none  remained.  'Iliis 




(/)     55H 

w        50 

\     45- 

._     '^0- 
C     35-1 


>.  3oH 

W    25- 

I    ^°- 
CZ      15-1 


~B        5-1 



I  \ 






■^^^3    NEW    RECRUITS 

I    I    r 

Sept    Oct   Nov   Dec    Jon 

I    r 

Sept  Oct    Nov    Dec  Aug  Sept   Oct    Nov   Dec  July    Aug  Sept  Oct   Nov    Dec 

1972  1973  1974 

FIG.  2.  ConilMrisiin  of  imindnliiui  density  of  new  rn-nnts  nml  ulilcr  i/ciir  cldssiK  of  L.  aiiKulifera  in  the  iimntli^  m  irhicli  I  Ik  two 
Uroiips  (ire  ciixiliidi.itiiiiiiii.ihnL 

Vol.  94  (4) 

October  30, 1979 


species  continued  to  be  abundant  in  local  Spar- 
tina  marshes  but  did  not  return  to  the  seawall. 
Casual  observation  of  other  seawalls  in  the  area 
showed  that  while  L.  nngnlifcra  was  frequently 
present,  L.  irrorata  was  rarely  present,  sug- 
gesting that  it  was  less  able  to  adapt  to  that  en- 
vironment. Although  these  were  the  only  two 
supratidal  mollusks  on  seawalls  several  inteitidal 
mollusks  inhabited  the  canal  bottom. 

Several  species  of  algae  grew  upon  the  en- 
crusted basal  zone  of  the  seawall.  Tlie  following 
species  of  Cyanophyta  (blue  green)  were  found: 
Anacystiii  aeruginosa,  A.  montana.  Por- 
phip-iisiphon  noiarisii  Schizotkrix  arenaria.  S. 
calcicola,  Microcoleus  lyngbyaceus,  Entnphysalis 
de^ista,  and  Mastigncoleus  testanim.  The  last  two 
and  Schlzothrir  calcicola  were  found  boring  into 
oyster  and  barnacle  shells  in  the  upper  parts  of 
the  encrusted  zone.  In  addition  to  the  blue  green 
algae,  several  species  of  red  and  green  algae  were 
consistantly  found  on  the  lower  20  cm  of  seawall, 
usually  where  it  was  protected  by  an  overhang  of 
oyster  growth  and  not  subject  to  excessive  desic- 
cation. The  following  species  of  Rhodophyta  (red 
algae)  were  found:  Polysiphonia  suhtilissima, 
Centroceras  clavulatmn,  and  Ceramium 
fastigiatum.  Chlorophyta  (green  algae)  included: 
iUva  sp..  Entcromorplia  roiiipin^m.  E.  liitgnlittn. 
Chaetomoi-iyha  aerea.  Qadophora  delicatula,  and 
Qadophora  sp.  In  addition  numerous  diatom 
species  were  present.  Both  littorines  fed  in  this 
zone  but  actual  species  eaten  were  not  deter- 

Thus,  while  creation  of  seawalled  canals  has 
apparently  contributed  to  the  decrease  of  species 
diversity  in  Boca  Ciega  Bay  (Taylor  and  Saloman, 
1968;  Sykes  and  Hall,  1970)  some  species  are  able 
to  adapt  to  the  conditions,  especially  if  an  inter- 
tidal  zone  is  present.  Since  much  of  the  shallow 
water  area  of  this  bay  formerly  consiting  of 
grass  flats,  mangrove  shores  and  Spartina  marsh- 
es has  been  converted  to  seawalled  canals  (Simon, 
1974),  we  felt  that  studying  snails  in  this  type 
of  environment  might  add  to  knowledge  of  some 
long-term  effects  of  "dredge  and  fill"  as  well  as 
provide  information  of  the  life  cycle  of  L.  anguli- 


Pupulation  fluctuations 

Population  changes  were  studied  by  means  of 
censuses  of  all  L.  angulifera  in  two  areas  of 
seawall.  Area  A  was  a  portion  of  seawall  13.2  m 
long  (eleven  120  cm  slabs).  Area  B,  10.8  m  long 
(nine  120  cm  slabs)  was  located  approximately  25 
m  from  Area  A.  All  snails  in  these  areas  were 
counted  every  2-3  weeks  from  October  1971 
through  June  1972.  and  approximately  each 
month  thei'eafter  through  May  1975,  with  addi- 
tional censuses  in  May  and  July  1976.  In  some  in- 
stances slightly  longer  intervals  elapsed  between 
counts.  The  seawall  was  140  cm  high  in  Area  A 
and  the  substrate  at  the  base  was  soft  mud:  the 
base  of  the  wall  was  encrusted  with  oysters  and 
barnacles.  In  Area  B  the  seawall  was  130  cm  high 
and  the  substrate  at  the  base  was  oyster  bar;  the 
base  was  also  encrusted  with  oysters  and  bar- 
nacles, although  the  zone  of  encrustation  was  not 
as  wide  as  in  Area  A  due  to  the  contour  of  the 
canal  bottom.  Total  counts  of  L.  angulifera  were 
converted  to  population  densities  expressed  as 
numbers  of  snails/m^  of  seawall  (Figure  1).  From 
September  through  December  of  each  year  new 
recruits  were  recorded  separately  from  previous 
year  classes  since  size  differences  between  the 
two  groups  were  evident  during  censusing 
(Figure  2). 

Total  shell  height  (from  base  of  aperature  to 
tip  of  spire)  of  random  samples  (including  all 
snails  on  an  area  of  exposed  seawall  at  all  levels) 
of  usually  at  least  100  snails  was  measured  to  0.1 
mm  with  vernier  calipers  to  study  the  pattern  of 
size  distribution  and  growth.  Sizes  of  samples 
taken  after  the  1974  red  tide  were  small  because 
of  the  decrease  in  snail  population  then,  but  such 
samples  represent  a  large  percentage  of  the  re- 
maining population.  The  samples  were  taken  near 
to  but  not  in  census  areas  and'  usually  were 
retui-ned  to  the  seawall  after  measurement  to 
avoid  depleting  the  population  and  disturbing  the 
census  areas.  Size  distribution  curves  (Figure  3) 
are  based  on  size  classes  of  1  mm  intervals. 
Figure  4  depicts  the  seasonal  variation  in  mean 
shell  height  for  the  population  as  a  whole. 
Growth  of  new  recruits  during  1972-73  was  com- 
pared with  that  of  older  snails  (Figure  5)  by 
calculating  mean  shell  height  of  new  recruits  and 
older   snails   separately.    During   months    when 


October  30, 1979 

Vol.94  (4) 









19  Oct..  1972 

Size  Class 

FIG.  3.  Seasonal  variations  in  size  class  distribution  o/L.  angulifera /row  October  1971  through  May  1975. 

Vol.94  (4) 

October  30, 1979 








Size  Class 

FIG.  3.  (continued) 


October  30. 1979 

Vol.  91  (J) 











i  S  S  ^  2 

FK'i.  1. .SV ii.<iiii(il  riiniilitiiix  In  niciiii  sliill  In  iijlit  n/'L.  anpulifera. 

sizes  of  the  two  groups  overlapped  a  "cut-off' 
point  based  on  relative  numbers  of  individuals  in 
different  size  classes  was  used.  The  same  methods 
of  cen.-^usinp  and  shell  height  measurement  were 
continued  during  and  after  the  high  tide  and  red 
tide  episf)des.  Particular  attention  was  paid  to 
resultant  changes. 

In  addition  to  the  1974  red  tide  there  was  a 
less  extensive  outbreak  in  the  summer  of  1971. 
Accurate  census  data  were  not  obtained  at  this 
time  because  snails  in  the  census  areas  were 
disturbed  during  other  studies,  but  data  available 
indicate  that  there  was  a  decline  in  population 
density  as  a  result  of  exposure  to  two  "patches" 
of  red  tide. 

Zonation  Patterns 

Both  the  vertical  migration  and  zonation  level 
of  adult  snails  were  investigated  during  the 
spawning  season  from  May  to  October.  Addi- 
tionally the  developing  zonation  pattern  of  new 
recruits  was  studied  from  November  1971 
through  May  1972.  The  position  of  snails  on  the 
seawall  was  designated  by  dividing  the  seawall 
into  six  zones  from  biise  to  cap.  The  lowermost 
zone  (zone  1)  consisted  of  that  part  of  the  seawall 
encrusted  with  oysters  and  barnacles  and  varied 
from  30-40  cm  deep  depending  upon  the  contour 
of  the  canal  bottom.  The  next  higher  zone  (zone 
2)  included  the  area  from  the  top  of  the  encrusta- 
tion to  a  dark  stain  on  the  seawall  and  w;us 
uniformly  20  cm  deep.  The  uppermost  limit  of 
this  zone  was  that  of  Mean  High  Water  Spring 
and  the  base  of  the  seawall  was  at  or  just  above 

Mean  Low  Water.  The  remaining  portion  of  the 
seawall  was  arbitrarily  divided  into  four  addi- 
tional zones  (zones  3-6)  each  20  cm  deep.  All 
zonation  study  was  done  in  Area  A  and  snails 
therein  were  not  moved  or  disturbed. 

To  deteiTnine  the  zonation  pattern  of  adult 
snails,  numbei-s  of  individuals  in  each  of  the  six 
zones  in  from  2-3  sections  of  seawall  (about 
75-100  animals)  were  counted  and  that  number 
converted  to  percent  of  all  snails  counted.  Water 
level,  time  of  day,  and  general  weather  conditions 
were  recorded  at  each  observation.  If  the  tide  was 
sufficiently  low  to  uncover  the  entire  seawall  the 
water  level  was  recorded  as  "0".  Since  snails  were 
not  ordinarily  found  below  the  base  of  the 
seawall,  specific  data  on  tides  lower  than  this 
were  not  obtained.  Observations  included  the 
hours  from  aiiproximately  (1900  to  23iHi  on  17 
different  days  during  both  neap  and  spring  tides 
from  26  May  to  2  October  1971,  although  not  all 
days  included  the  veiT  late  observations.  Observa- 
tions were  usually  made  four  to  five  limes  per 
day,  but  as  few  as  three  and  as  many  as  eight 
were  made  on  .some  days. 

Since  newly  recruited  snails  were  not  seen 
readily  in  the  encrusted  zone,  the  zonation  pat- 
tern of  these  .small  snails  was  studied  only  when 
zone  I  was  under  water  and  small  snails  visible 
on  bare  seawall.  In  this  case  the  relationship  be- 
tween the  size  of  the  snail  and  the  di.stance  above 
the  waterline  was  determined  and  zones  only  10 
cm  wide  were  used.  Figure  6  shows  percentages 
of  snails  at  different  levels  above  the  water  and 
placement  of  snails  as  a  function  of  size.  Tlie  two 

Vol.  94  (4) 

October  30. 1979 


sets  of  data  on  zonation  show  different  aspects  of 
the  life  cycle.  One  illustrates  the  adult  pattern  of 
zonation  and  the  other  the  development  of  that 


Population  Changes 

a)  General 

Data  in  Figures  1  through  5  show  that  there 
are  seasonal  changes  in  population  density  and 
mean  shell  height  reflecting  the  seasonal  nature 
of  the  L.  angulifera  reproductive  cycle  in  this 
area.  The  first  new  recruits  settled  on  the  seawall 
sometime  between  late  July  and  mid-August  of 
each  year  studied.  Increases  in  population  density 
were  evident  by  the  end  of  August  or  early 
September;  there  then  followed  a  period  of  from 
as  few  as  39  days  to  as  many  as  113  days  when 
the  population  density  increased.  Greatest 
population  density  was  reached  during  peak 
recruitment  in  the  fall  of  each  year  studied.  Ac- 
tual dates  varied  from  late  September  in  1974  to 
mid-November  in  1973,  but  after  these  dates  the 
population  declined  steadily  and  reached  a  yearly 
low  in  July  or  August  just  before  recruitment 
began  again. 

The  smallest  snails  settling  on  the  seawall 
were  1..5  mm  total  shell  height  but  most  newly 
settled  individuals  were  in  the  2.0-2.9  mm  size 

class  and  had  five  or  six  whorls.  Attempts  to  find 
presettlement  snails  in  the  environment  failed,  so 
that  the  course  of  development  from  swimming 
veliger  with  a  maximum  shell  length  of  only  0.13 
mm  (Gallagher  and  Reid.  1974)  to  those  capable 
of  settlement  at  1.5  mm  as  found  here  is 
unknovm.  Length  of  time  spent  in  the  pelagic 
stage  can  be  estimated,  however.  In  1971,  peak 
spawning  occurred  during  late  August  and  early 
September  (Gallagher  and  Reid,  1974)  and  peak 
recruitment  occurred  in  early  November  (Figures 
1  and  2).  Thus  about  eight  to  ten  weeks  elapsed 
between  maximum  spavraing  and  maximum 
recruitment;  this  likely  represents  the  length  of 
pelagic  life  for  this  snail. 

Comparison  of  Figures  1  and  4  shows  that 
mean  shell  height  of  the  population  varies  in- 
versely with  density.  This  is  due  in  part,  of 
course,  to  the  presence  of  large  numbers  of  new 
recruits  during  certain  months,  but  in  years  of 
greatest  overall  density  snails  tended  to  remain 
smaller  than  in  years  of  overall  low  density.  A 
weak  positive  correlation  (r  =  0.74)  between  densi- 
ty and  mean  shell  height  of  adult  snails  com- 
pared and  tested  by  the  X^  method  was  found. 

Size  distribution  curves  (Figure  3)  show 
seasonal  changes  in  recruitment  and  growth. 
There  is  a  distinct  bimodal  pattern  in  late  sum- 
mer   and    fall,    although    numbei-s    of    adults 


.E  14- 
^   12- 


a>  10- 


-C     6- 


c  4- 

<U    2- 






Sept        Oct        Nov        Dec        Jon        Feb        Mor        Apr        May       June       July        Aug        Sept        Oct 

1972  1973 

FIG.  .5.  Gymparisnn  of  the  mean  shell  heights  nf  new  recruits  and  idder  iiear  elasses  of  {,.  angulifera  in  1972-7-1  to  show  dif- 
ferences in  growth  rate  heticeen  t he  t  wo  i/roups. 


October  30, 1979 

Vol.94  (4) 

representing  previous  year  classes  were  much 
smaller  than  those  of  new  recruits.  By  the  end  of 
December  the  two  distinct  sizes  could  not  be 
detected  by  gross  observation  but  were  still  evi- 
dent in  size  distribution  curves.  By  March, 
however,  size  distribution  curves  were  no  longer 
distinctly  bimodal,  indicating  that  growth  of  new 
recruits  was  greater  than  that  of  older  year 
classes  and  that  they  were  "catching  up"  to  them 
in  size.  The  total  size  range  at  this  time  was 
large,  ranging  from  3.0  to  20.0  mm  shell  height 
(except  in  1974  following  the  red  tide  outbreak). 
In  summer,  during  spawning  and  just  before 
recruitment  began,  the  size  range  was  much 
smaller,  being  from  9.0  to  18.0  mm  in  1972  and 
11.0  to  20.0  mm  in  1973.  Since  snails  can  begin 
spawning  at  approximately  10.0  mm  shell  height 
(Gallagher  and  Reid,  1974).  these  data  indicate 
that  most  surviving  recruits  reached  spawning 
size  toward  the  end  of  their  fii-st  year  or  at  about 
9-10  months  post  metamorphosis.  Thus  the  size  of 
the  total  population  in  May,  which  is  the  start  of 
the  spawning  seasfjn  in  the  Tampa  Bay  area,  can 
be  regarded  as  the  size  of  the  breeding  population 
at  the  start  of  any  given  breeding  season.  Figure 
5,  which  compares  mean  shell  heights  of  new 
recruits  and  older  year  classes  from  September 
1972  through  June  1973,  shows  the  difference  in 
growth  rates  of  the  two  groups  of  snails.  New 
recruits  grew  rapidly  through  the  fall  and  winter 
while  older  year  classes  grew  little  or  not  at  all 
during  that  period  but  increased  in  size  from 
March  to  May.  Apparently  grovrth  is  minimal 
during  spawning  and  winter  months  for  adult 
snails  but  is  lapid  for  new  recruits  until  they 
reach  adult  size. 

b)  Miwtality 

Although  the  data  do  not  show  seasonal 
changes  in  mortality  rate  which  may  occur  in 
this  snail,  total  yearly  percent  mortality  can  be 
detennined  by  converting  the  decrease  in  popula- 
tion density  (from  highest  yearly  density  after 
fall  recraitment  to  lowest  yearly  density  just 
before  recruitment)  to  percent  of  snails  lost 
(Table  1).  This  gives  approximate  ten  month 
"mortality  rates"  of  58  and  57  percent  in  1971-72 
and  1972-73  respectively,  increasing  to  94.5  per- 
cent in  1973-74.  the  year  of  the  extensive  bloom 
of  (hjnitiixliiiinin  breve  If  57-58  jiercent  is  con- 
sidered a  normal  ten  month  mortality  (average 

5.75  percent  per  month)  expected  yearly  mortal- 
ity can  be  extrapolated  to  be  about  70  percent  in 
an  average  year.  Older  year  classes  continue  to 
decrease  in  density  from  September  through 
December  (Figure  2)  while  new  recruits  show  a 
sharp  increase  in  density  for  a  period  of  six  to 
twelve  weeks  during  recruitment.  Therefore  there 
is  a  sharp  decline  followed  by  a  more  moderate 
rate  of  decrease  (Figure  2).  Apparently  many 
new  reci'uits  do  not  survive  even  a  few  weeks  in 
the  intertidal  environment,  and  older  year  classes 
decline  in  numbers  throughout  the  year. 

The  percent  increase  in  snails  also  varied  in 
different  years  (Table  2).  Increase  during  recruit- 
ment in  Area  A  was  235  percent  following  losses 
from  the  July  1971  red  tide.  Due  to  lack  of  sum- 
mer census  data  for  Area  B,  the  percent  increase 
is  not  known.  Figure  1  shows  an  exceptionally 
heavy  recruitment  for  both  areas,  especially  Area 
B.  There  is  no  explanation  for  this  difference  but 
population  densities  in  the  two  areas  were 
similar  in  all  other  years  studied  (Figure  1).  Dur- 
ing the  next  two  years  there  was  a  90  percent  in- 
crease in  density  (though  actual  numbers  of  snails 
were  different)  possibly  representing  a  normal 
or  average  increase.  Percent  increase  was  excep- 
tionally large  (462  percent)  following  severe 
population  depletion  after  the  1974  red  tide; 
actual  population  size,  however,  was  greatly  re- 
duced. The  1971  summer  red  tide,  which  con- 
sisted of  only  two  "patches"  in  the  study  area, 
did  not  reduce  the  population  to  exceptionally 
low  densities  (Table  2). 

c)  Effects  of  extremely  high  tides  and  a  red 
tide  bloom 

During  the  extremely  high  tides  which  ac- 
companied Hurricane  Agnes  in  June  1972,  water 
completely  covered  seawalls  in  the  area,  causing 

TABLE  1.  Percent  decrease  in  snail  population  (Area  A)  from 
highest  yearly  density  at  peak  recndtment  in  fall  of  one  year 
to  lowest  yearly  density  before  recruitment  starts  in  the 
folUnciny  year. 

1971-72     1972-73     1973-74 

High  Density* 




Low  Density 




Total  Decrease 




Pei'cent  Decrease 




'Denisitv  =  number  of  individuals/m' seawall. 

Vol.94  (4) 

October  30, 1979 


TABLE    2.  Percent    increase    in    snail    poptdation    during 
recruitment  -Area A 





Low  Efensity' 





High  Density 





Total  Increase 





Percent  Increase 





'Density  =  number  of  snails/m"  seawall. 

L.  angulifera  to  crawl  onto  the  cap  of  the 
seawall.  This  left  many  individuals  stranded  on  a 
horizontal  surface.  Fifty  stranded  snails  were 
marked  with  waterproof  paint  to  determine  if 
they  would  return  to  the  vertical  portion  of  the 
seawall.  After  five  days  five  of  them  had 
returned,  but  subsequent  observations  showed  no 
more  did  so.  There  was  a  sharp  drop  in  popula- 
tion density  from  59/m^  to  46/m^  in  Area  A 
(Figure  1)  immediately  after  the  storm.  The 
decline  was  even  greater  in  Area  B  which  had  ex- 
ceptionally large  numbers  of  snails  from  the 
heavy  fall  1971  recruitment.  Resultant  loss  from 
these  high  tides  was  27  percent  in  Area  A  and  42 
percent  in  Area  B.  As  a  consequence  of  greater 
loss  in  Area  B,  population  densities  for  the  two 
areas  became  similar  and  remained  so  during  the 
remainder  of  the  study.  These  population  losses 
occurred  suddenly  over  the  course  of  a  few  days, 
and  there  was  no  subsequent  increase  indicating 
that  stranded  snails  had  returned  to  the  seawall. 
Thus,  such  stranding  constitutes  a  lethal  hazard 
for  this  species  in  a  seawall  environment.  It  is 
possible  that  in  a  mangrove  habitat  snails  would 
be  able  to  move  up  and  down  greater  distances 
on  mangrove  trees  and  probably  not  be  stranded. 
In  a  Spartina  marsh,  snails  would  probably  re- 
main submerged  near  the  tops  of  Spartina  stalks 
and  if  wave  action  or  currents  were  strong  be 
washed  off  and  lost.  Most  snails  remained  sub- 
merged just  under  the  cap  of  the  seawall  for 
several  hours  during  the  hurricane.  Lowest  densi- 
ty for  that  year  was  32  snails/m^  (Figure  1)  so  ef- 
fects of  Hurricane  Agnes  did  not  reduce  sharply 
the  actual  numbers  of  spawning  snails.  No  doubt 
the  extremely  large  numbers  of  snails  as  a  result 
of  the  heavy  1971  recruitment  somewhat 
ameliorated  the  damaging  effects  of  Hurricane 
Agnes  on  the  population. 

An  outbreak  of  red  tide  caused  by  the 
dinoflagellate  Gymnodinium  breve,  occurred  in 
the  study  area  from  February  through  March, 

1974.  In  the  canal  it  appeared  as  patches  of  in- 
fested water  and  was  not  present  continuously.  It 
was  most  prevalent  at  high  tides  and  tended  to 
concentrate  in  the  upper  30  cm  of  water.  Often 
the  accumulation  was  heaviest  adjacent  to  the 
seawall  as  if  the  wind  was  pushing  the  dino- 
flagellates  against  the  seawall  which  then  acted 
as  a  barrier  to  its  dispersal,  hence  some  very  high 
concentrations  occurred  here.  The  patch  almost 
always  dispersed  on  the  outgoing  tide  or  if  the 
wind  shifted.  A  new  patch  sometimes,  but  not 
always,  occurred  with  the  next  incoming  tide. 
Most  patches  extended  between  5  and  10  m  out 
from  the  wall  and  lasted  approximately  six 
hours.  In  the  study  area,  most  occurred  from 
mid-February  through  March,  but  the  outbreak 
in  the  Tampa  Bay  region  lasted  from  January 
through  April.  Following  the  appearance  of  red 
tide  in  the  canal,  many  L.  angulifera  were  found 
dead  and  dying  in  the  mud  at  the  base  of  the 
seawall.  Moribund  animals  seemed  paralyzed  and 
unable  to  withdraw  into  shells  or  attach  to 
substrate.  Many  recovered  when  placed  in  non- 
infested  seawater  in  laboratory  aquaria  but  no 
controlled  studies  to  determine  effects  of  ex- 
posure time  and  concentration  were  done. 

There  was  a  drastic  reduction  in  the  snail 
population  as  a  result  of  the  red  tide.  The  popula- 
tion density  on  24  January  1974  before  any  red 
tide  appeared  in  the  canal  was  27  and  31 
snails/m^  in  Areas  A  and  B  respectively.  This  is 
comparable  to  densities  in  those  areas  on  19 
January  1973  (36  and  32  snails/m^  Areas  A  and 
B).  On  25  February  1974  a  few  days  after  the 
first  appearance  of  red  tide  in  the  canal  popula- 
tion densities  were  only  8  and  9  in  the  two  areas 
(A  and  B).  In  1973  density  reduction  after  a  com- 
parable time  was  only  by  three  snails  in  Area  A 
and  none  in  Area  B.  There  were  further  reduc- 
tions in  the  population  until  low  densities  of  2.6 
and  2.3  individuals/m'  were  reached  in  the  sum- 
mer of  1974  (Figure  1),  representing  a  94.5  per- 
cent reduction  from  peak  density  in  November  to 
yearly  low  in  August  (Table  1).  Density  of  the 
breeding  population  in  May  of  that  year  was  only 
3  snails/m^  in  the  two  areas  studied.  Presumably 
similar  changes  occurred  in  other  habitats  in  the 
area  so  that  the  breeding  population  of  L. 
angulifera  would  be  much  reduced  in  the  Tampa 
Bay    region    for    the     1974    spawning    season. 


October  30, 1979 

Vol.94  (4) 

Recruitment  in  1974  began  at  the  end  of  July  and 
reached  a  peak  in  late  September,  slightly  earlier 
than  in  previous  years.  The  peak  density  reached 
in  the  fall  of  1974  following  the  red  tide  of  the 
previous  winter-spring  was  15  and  8  snails/m^  in 
Areas  A  and  B,  far  below  peak  densities  reached 
in  other  years  (Figure  1)  even  though  the  percent 
of  increase  was  much  greater  than  in  previous 
years  (Figure  2).  In  May  1975  population  den- 
sities were  12  and  9  indicating  that  the  L. 
angulifera  population  was  not  back  to  pre-red 
tide  levels  and  still  had  a  very  reduced  breeding 
population.  One  year  later  in  May  1976  popula- 
tion densities  were  15  and  13  snails/m^  in  Areas 
A  and  B,  still  below  comparable  dates  for  other 
years.  The  last  census  taken  (July  1976)  showed 
population  densities  of  12  and  5  snails/m^  in  the 
two  areas  counted.  Apparently  the  effects  of  red 
tide  are  long  lasting  for  this  snail  for  after  two 
years  the  population  had  not  recovered  in  terms 
of  density. 

A  marked  increase  in  mean  shell  height  from 
10.6  mm  on  24  January  to  13.8  mm  (a  total  of  3.2 
mm)  on  25  February  1974  accompanied  the  initial 
sharp  decline  in  population  density.  On  com- 
parable dates  in  previous  years  shell  heights  in- 
creased by  1.2  mm  in  1973  and  0.4  mm  in  1972.  In 
addition,  on  24  January  (before  red  tide)  sizes 
ranged  from  4.0  mm  to  20.0  mm  (Figure  3).  On  25 
February  (after  red  tide)  sizes  ranged  from  9.0  to 
18.0  mm.  Since  it  is  unlikely  that  snails  in  the  4.0 
to  4.9  mm  size  class  could  grow  to  9.0  mm  in  that 
time,  the  data  apparently  indicate  that  mortality 
was  greater  among  the  small  snails;  indeed,  none 
of  the  very  small  snails  remained.  Nearly  all  in- 
dividuals still  alive  were  of  adult  size.  It  is 
probable,  therefore,  that  the  breeding  population 
in  May  1974  was  made  up  largely  of  animals  two 
or  more  years  old.  Thus,  although  few  snails  sur- 
vive through  two  spawning  seasons,  those  that  do 
would  be  important  in  species  survival  should  an 
event  which  kills  new  recruits  differentially  oc- 

Zonation  Patterns 

a)  Adult  zonation  and  vertical  movements 
Adult   L.    angidifera  were  never   found   sub- 
merged but  always  occurred  above  the  water 
line.  During  low  tide  periods,  snails  might  mi- 
grate down  into  the  encrusted  zone  to  feed,  but 

as  they  became  wet  with  the  rising  tide,  they 
moved  up  and  remained  out  of  the  water.  In  the 
laboratory,  animals  placed  in  aquaria  with  small 
amounts  of  water  responded  by  crawling  out  of  it 
within  5-10  minutes.  Lenderking  (19.54)  noted 
similar  behavior,  and  Hayes  (1929),  Evans  (1965), 
and  Bingham  (1972)  demonstrated  similar 
responses  in  other  species  of  Littorina.  When 
kept  in  aquaria  for  periods  of  two  or  more  weeks, 
however,  L.  angulifera  migrated  down  to  the 
water  level  on  occasion  and  fed  from  algae 
covered  rocks  or  shells.  Records  indicate  no 
periodicity  to  these  migrations  but  tidal  tanks 
were  not  used.  In  this  species,  only  spawTiing  ap- 
peared to  have  true  tidal  and  lunar  periodicities 
(Lenderking,  1954;  Gallagher  and  Reid,  1974). 

Data  obtained  from  observations  on  vertical 
migrations  of  adult  snails  on  the  seawall  show 
that  most  L.  angulifera  were  found  in  zones  3 
and  4  or  between  60  and  100  cm  above  the  base  of 
the  seawall  in  Area  A.  Measurements  of  the 
water  level  at  different  tidal  phases  showed  that 
extreme  high  spring  tides  generally  reach  no 
higher  than  80  cm  on  the  seawall,  mean  high 
spring  tide  was  at  the  top  of  the  dark  stain  on 
the  seawall  (zone  2),  and  mean  low  water  just 
below  the  base  of  the  seawall  in  the  study  area. 
Actual  measurements  on  the  seawall  varied  with 
the  contour  of  the  canal  bottom,  resulting  in  nar- 
rowing of  the  encrusted  zone  (zone  1),  but  the 
pattern  of  zojiation  in  terms  of  tidal  level  is  the 
same,  only  the  measurements  are  different.  These 
observations  show  that  L.  augulifera  is  a  supra- 
tidal  snail  occupying  a  zone  corresponding  to 
the  level  of  high  spring  tides  and  almost  always 
remaining  out  of  the  water.  Since  it  is  a  species 
of  quiet  water  areas  and  wave  splash  is  not  a 
factor,  it  is  thus  seldom  subject  to  wetting 
from  spray  as  are  some  supratidal  animals. 

Movements  into  lower  zones,  presumably  to 
feed,  took  place  only  when  those  zones  were  ex- 
posed but  did  not  occur  at  every  exposure.  Data 
presented  in  Table  3  show  that  at  any  given  low 
tide,  whether  neap  or  spring,  usually  less  than  50 
percent  of  the  adult  snail  population  migrated  in- 
to the  encrasted  zone,  indicating  such  migrations 
for  adults  are  relatively  infrequent.  Dates  of 
heaviest  migration  occurred  during  more  humid 
periods  when  rain  had  occurred  or  when  low 
tides  occurred  in  evening  or  early  morning  hours. 

Vol.  94  (4) 

October  30, 1979 


Apparently  snails  were  more  likely  to  move  when 
relative  humidity  was  high.  L.  auyulifem  did  not 
crawl  in  the  mud  at  the  base  of  the  seawall  even 
during  very  low  tides  but  always  remained  on 
the  upright  seawall;  thus,  they  never  moved 
lower  than  mean  low  water,  and  usually  re- 
mained well  above  this  level.  The  same  pattern  of 
zonation  was  also  seen  in  Sixuiinn-nvdngnwe 
areas,  where  snails  were  found  only  on  stems  and 
prop  stems  of  mangroves  or  Sixviina  stalks,  not 
crawling  on  sand  or  mud  at  bases  of  these  plants. 

b)    Zonation  in  new  recruits 

Newly  recruited  L.  anguUfera  remained  close 
to  the  waterline  in  a  zone  wetted  by  the  minimal 
wave  wash  in  the  canal.  This  zone  was  very  nar- 
row, usually  not  exceeding  10  cm.  Snails  nearly 
always  moved  up  and  down  so  as  to  remain  in 
this  wet  zone,  but  they  remained  in  the  encrusted 
zone  during  ver\'  low  tides  and  did  not  move  out 
over  the  mud  at  the  base  of  the  canal. 

Smaller  snails  are  closest  to  the  waterline  and 
there  is  a  progressive  increase  in  size  as  distance 
fi-om  the  water  increases  until  the  snails  reach 
adult  size  when  they  assume  the  adult  position 
and  are  likely  to  be  found  distributed  throughout 
the  supratidal  zone  (Figure  6).  There  is  nearly 
always  a  small  percentage  of  adult  snails  near 
the  waterline  since  snails  go  to  the  water  (though 
they  do  not  submerge),  probably  to  prevent  ex- 
cessive desiccation.  During  November,  when 
mean  size  is  small  due  to  large  numbers  of  new 
reciTiits,  between  62.4  and  65  percent  of  all  snails 
were  within  10  cm  of  the  waterline,  and  between 
17  and  25  percent  were  from  10-20  cm  of  it.  By 
December  and  January,  the  percent  of  snails 
within  10  cm  of  the  waterline  had  decreased  to 
between  22  and  30.5  percent.  Sizes  of  such  snails 
remained  small  but  there  were  fewer  of  them. 
Data  presented  in  Figure  6  show  changes  in  zona- 

TABLE  3.  MUjratiiin  into  encmsted  z<ine  2t)May  tii  2  October  1972. 

tion  pattern  of  new  recruits  as  they  grow  to 
.spawiing  size.  With  the  exception  of  the  unusual- 
ly low  zonation  pattern  seen  for  14  March,  there 
is  a  general  rise  in  zone  level  of  this  species  as 
the  size  of  snails  increases;  adult  size  is  reached 
when  animals  are  zoned  at  the  level  of  high  spr- 
ing tides.  This  occurs  in  May  at  the  start  of  the 
spawiiing  season  when  most  new  recruits  have 
reached  adult  size.  These  observations  also 
showed  that  during  the  fall  and  winter  months, 
mature  snails  from  previous  year  classes  re- 
mained at  the  supratidal  level;  there  was  no 
seasonal  shift  in  zonation  pattern  of  adults  as  has 
been  I'epoited  for  other  intertidal  snails  (Frank. 
1965;  Palant  and  Fishelson,  1968).  Only  the  new 
recruits  shifted  from  a  waterline  position  where 
they  remained  wet  to  a  dr>'  position  as  they  grew 
to  adult  size.  Thus,  the  change  in  zonation  pat- 
tern seen  as  postlarval  snails  reach  spawning  size 
can  be  considered  a  developmental  phenomenon. 

The  results  presented  here  can  best  be  sum- 
marized in  Figure  7  which  illustrates  yearly 
changes  in  a  population  of  L.  anguUfera  in  the 
Tampa  Bay,  Florida,  area.  In  this  area  all  the  life 
history  stages  are  seasonal,  therefore,  it  is  easy 
to  delimit  them.  Spawning  occurs  during  the 
wanner  months  of  the  year  (May  to  October).  The 
pelagic  larvae  also  develop  and  begin  to  settle 
during  this  time  but  peak  recruitment  is  reached 
in  the  fall  8  to  10  weeks  after  peak  spawning. 
Juveniles  grow  rapidly  during  cooler  months  of 
fall,  winter  and  early  spring;  at  the  same  time 
they  attain  the  adult  zonation  pattern.  Thus,  dur- 
ing growth  to  adult  size  there  is  a  change  from  a 
water-line  position  to  a  supratidal  position.  By 
late  May  most  of  the  young  snails  are  ready  to 
spawn.  Population  changes  and  size  distribution 

Percent  Snails  moving 
into  Encrusted  zone 

Number  of  Days  Seen 

Percent  of 

in  Encrusted  zone 

Total  davs 

19  days 


.5  davs 




2  days 


2  days 


Less  than  ICf  o 

10  ■  25% 

2.5 -.50% 

More  than  75% 

Total  number  of  days  observed  —  47 
The  percent  of  snails  seen  in  the  encrusted  zone  during  low  tides  on  47  different  days  of  the  1972  spawning  season.  The  days 
include  both  neap  and  spring  tides. 


October  30, 1979 

Vol.  94  (4) 


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FIG.  6.  Development  of  the  zonation  pattem  in  L.  angulifera.  The  distance  above  the  waterline  as  percent  total  snail  population  is 
related  to  median  shell  height.  (Median  shell  height  is  used  here  rather  than  mean  shell  height  in  order  to  eliminate  bias  in- 
troduced by  averaging  the  size  of  an  adult  snail  which  may  be  near  the  waterline— as  mentioned  such  snails  do  occasionally 
migrate  to  the  waterline  but  would  belong  to  the  adult  group  mther  than  the  new  recntits  whose  zonation  pattern  this  figure 

Vol.94  (4) 

October  30. 1979 




12   FEBRUARY.  1972 
















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October  30, 1979 

Vol.94  (4) 

patterns  reflect  these  chanpes.  The  yearly  cycle  in 
this  area  is  much  more  sharply  delineated  than 
in  the  Miami  area  where,  as  shown  by  Lender- 
king  (1954),  spawning  occurs  throughout  the  year. 
It  follows,  as  she  showed,  that  other  life  stages 
are  more  or  less  continuous  in  that  area  also.  No 
doubt  the  greater  seasonal  variation  in 
temperature  in  the  Tampa  Bay  area  is,  in  part, 
responsible  for  differences  seen  between  the  two 

Data  and  observations  indicate  that  L. 
angidifera  is  a  fast-maturing,  probably  short- 
lived species  much  like  LItfnrina  lineatcu  L. 
linealatcu  and  L.  ziczcw  as  reported  by  Borkowski 
(1974).  Most  snails  begin  spawning  about  9  to  10 
months  after  metamorphosis.  About  70  percent  of 
them  d(j  not  reach  a  second  spawTiing  season, 
much  the  same  percent  Borkowski  (1974)  found 
for  species  of  the  Littorina  ziczae  complex. 

Population  changes  in  this  snail  are  affected  by 
a  variety  of  factors.  These  include  unusual  en- 
vironmental events  that  do  not  occur  regularly 
ever>'  year.  During  the  course  of  this  study  two 
such  events,  extremely  high  tides  and  a  red  tide 
bloom,  occurred.  Because  population  changes  in 
groups  of  animals  are  susceptible  to  events  of  this 
nature  which  vary  from  year  to  year,  it  is  dif- 
ficult to  ascertain  just  what  "average"  or  "nor- 
mal" changes  are.  This  could  only  be  done  by 
observations  over  such  a  long  period  that  effects 
of  unusual  events  would  cancel  out.  Obviously  a 
three  year  study  period  is  too  short.  In  spite  of 
this,  however,  changes  occurring  in  the  unusual 
years  were  compared  with  changes  when  no 
unusual  events  occurred.  In  this  way  some  indica- 
tion of  the  magnitude  of  these  environmental 
stresses  was  obtained.  The  results  show  that 
while  these  events  caused  drastic  changes  in- ac- 
tual population  numbers,  the  general  changes  ac- 
companying the  yearly  life  history  remained  the 
same.  Of  the  two,  the  red  tide  bloom  was  more 
damaging  than  the  extreme  high  tides.  Not  only 
were  the  immediate  effects  of  the  red  tide  bloom 
more  severe  but  there  were  long  term  changes  in 
p<jpulation  density  as  well.  Further,  since  the  red 
tide  differentially  killed  small  snails,  the  com- 
position of  the  spawning  pt^pulation  the  following 
year  consisted  primarily  of  older  snails.  Thus,  the 
older  group,  small  in  numbers  compared  to  the 
most  recently  spawTied  group,  had  to  make  up  the 

deficit  caused  by  the  high  mortality  among  new 
recruits.  As  the  data  show,  this  caused  a  lasting 
effect  on  population  density. 

Upon  settling,  very  small  snails  remain  close  to 
the  waterline  and  move  upward  as  they  grow  and 
mature  so  that  by  the  beginning  of  the  spawning 
season   in   May  the  adult  zonation  pattern  has 
developed.  Other  investigators  have  alsf)  reported 
an  upshore  size  gradient  of  this  type  for  inter- 
tidal    moUusks.    Smith    and    Newell    (1954) 
demonstrated  that  this  occurred  with  L.  littorea 
until  the  adult  zonation  pattern  was  reached  at 
about   one  year  of  age,  after  which   individual 
snails  tended  to  remain  at  the  level  they  had 
reached  at  that  time.  They  did  not   report  any 
vertical  migrations  of  adults  as  noted  here  for  L. 
aiHiulifcm.  and  by  Bingham  (1972)  for  L.  irmrata. 
Palant    and    Fishelson    (1968)    found    the   same 
phenomenon  for  L.  punctata  in  that  small   in- 
dividuals remained  clustered  in  a  wet  zone  near 
the  waterline,  while  large  individuals  were  found 
higher  on  the  seawall.  Chow  (1975)  reported  an 
upshore    size    gradient    in    L.    .'icutnlata.    with 
smaller  snails  being  found  closer  to  the  water. 
Frank  (1965),  in  a  study  of  population  changes  in 
the  limpet  Acmaea  digitalL<!.  found  a  similar  size 
gradient,  with  largest  and  oldest  animals  being 
found   higher    in   the    intertidal    zone.   Vermeij 
(1972),   in  an  excellent  review,  reported  such  a 
gradient    for   high    intertidal    to   supratidal 
mollusks  during  post  larval  stages  but  the  op- 
[josite  gradient  for  those  whose  range  was  low  to 
mid-intertidal.    Chow    (1975)    found    that    while 
small   snails  were   less  resistant  to   desiccation 
than  large  ones,  all  sizes  were  resistant  to  desic- 
cation encountered  in  the  envii-onment.  Results  of 
preliminary,  as  yet   unpublished,  experiments 
show  that  the  same  is  true  for  L.  augulifcra.  The 
zonation   pattern   of  juvenile   snails   results   in 
favorable  placement  in  respect  to  food  and  pro- 
bably helps  to  ensure  frequent  feeding  excui-sions. 
TViis  is  likely  necessary  for  snails  to  grow  to 
maturity  by  the  spawning  season  in  May.  It  may 
\:>e  more  imiX)rtant  in  determining  the  zonation 
pattern  of  juveniles  than  resistance  to  desicca- 
tion. It  is  also  possible,  however,  that  placement 
lower  intertidally  was  an  important  factor  in  the 
greater  mortality  of  small  snails  during  the  red 
tide  outbreak.  Larger  snails  remained  higher  on 
the  seawall  and  hence  had  a  better  chance  to 

Vol.94  (4) 

October  30, 1979 



'Srowth  of  1st  Year  Class  to  Spawning  Size 

Develop  men   ui  mOuII  Zonation  Patiern 




i  *::■ 

Growth  of  1st  Year  Class  to  Spawning  Size 

Development  of  Adult  Zonation  Pattern 

OCT        NOV       DEC.      JAN.       FEB     MARCH     APR       MAY      JUNE     JULY 
FIG.  7.  Diiifiniiii  mitt  ir  ifjinsciiiatiiiii  iiftlic  i/fitrlti  tiff 

escape  it.  Smaller  snails  also  may  be  more 
susceptible  to  red  tide  toxins,  but  tests  were  not 

There  is  some  evidence  that  snail  growth  may 
be  density  dependent  since  during  years  when  the 
lowest  density  of  the  year  is  high,  the  greatest 
mean  shell  height  for  that  year  is  lower  than  in 
years  when  the  lowest  density  for  the  year  is  low 
(Figures  1,  4).  VeiTneij  (1972)  reported  this  for 
the  bivalve  Tellina  tenuis  and  Frank  (1965)  found 
that  growth  of  Acmaea  digitalis  was  reduced  dur- 
ing crowding.  Frank  (1965)  suggested  that  food 
availability  may  be  a  factor,  and  such  may  also 
be  true  here,  although  Bingham  (1972)  found  that 
it  was  not  important  in  the  distribution  of  L.  ir- 
rorata  in  a  north  Florida  marsh  since  in  that  en- 
vironment an  excess  of  food  was  available  in  all 
areas.  The  situation  might  be  different  on  a  flat 
seawall  which  would  present  less  surface  area  for 
the  growth  of  food  organisms  than  would  a  marsh 
or  mangrove  habitat.  Gallagher  and  Reid  (1974) 
showed  that  L.  angnlifera  in  a  Spartina-ma.n- 
grove  area  had  a  larger  mean  size  than  those  on 
a  seawall,  suggesting  that  food  availability  may 
be  a  factor  in  a  seawall  environment. 

Although  this  study  illustrates  and  describes 
the  yearly  life  history  of  L.  angulifera  in  the 
Tampa  Bay.  Florida  area  much  remains  to  be  in- 
vestigated regarding  factors  regulating  these 
events.    Studies    encompassing    temperature 


histiiriiiifh.  angulifera  in  the  Tnnipii  liii/.  Ftundii.  lu-rn. 

tolerance,  desiccation  resistance,  and  identifica- 
tion of  food  organisms  are  planned. 

We  are  deeply  grateful  to  William  G.  Lyons, 
Supervisor  of  Invertebrate  Studies,  Florida  State 
Department  of  Natural  Resources,  Marine  Re- 
search Laboratory,  St.  Petersburg,  Florida,  for  his 
critical  reading  of  the  manuscript.  We  also  thank 
Ms  Karen  A.  Steidinger,  Laboratory  Supervisor, 
for  identification  and  measurement  of  the  Gym- 
riiidinium  breve  blooms,  and  Dr.  Harold  J. 
Humm,  Professor  of  Marine  Science,  University 
of  South  Florida,  St.  Petersburg,  for  confirmation 
of  the  algal  identifications.  We  express  great  ap- 
preciation to  Mrs.  Sally  D.  Kaicher  for  prepara- 
tion of  the  figures  and  to  Miss  Stephanie 
Schminke  for  the  typing.  Financial  support  has 
been  received  from  the  Eckerd  College  Faculty 
Development  Fund. 


Abbott.  R.  T.  1974.  Amenran  Seashells.  2nd  Ed.  Van  Nostrand 

Reinhold  Co..  New  York.  1974. 
Bandel,   K.   1974.  Studies  on  Littorina  from   the   Atlantic. 

Veliger  17:92-115. 
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on  the  direction  of  movement  of  the  supralittoral  gastropod 

Littorina  irmrata.  Bull.  Mar.  Sn.  22:.309-a35. 
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determining  the  intertidal  zonation  of  Littorina  planaxis 

Phillipi   1847  and  Littorina  scutulata  Gould  1849.  Veliger 



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Borkowski,  T.  V.  1974.  Growth,  monality  and  productivity  of 
South  Florida  Littorinidae  (Gastropoda:  Prosobranchia) 
Bull.  Mar.  Sci.  24:409437. 

Broekhuysen,  G.  J.  1939.  A  preliminary  investigation  of  the 
importance  of  desiccation,  temperature,  and  salinity  as  fac- 
tors controlling  the  vertical  distribution  of  certain  inter- 
tidal  marine  gastropods  in  False  Bay,  South  Africa.  Trans. 
Royal  Soc.  (if  South  Africa  28:255-292. 

Qiow,  V.  1975.  The  importance  of  size  in  the  intertidal  dis- 
tribution of  Littorina  scutulata.  Veliger  18:69-78 

Evans,  F.  1965.  The  effect  of  light  on  zonation  of  the  four 
periwinkles,  Littorim  littorea  (L.),  L.  obtv.sata  (L.)  L.  sax- 
alilis  (Olivi)  and  Melarapha  neritoides  (L.)  in  an  ex- 
perimental tidal  tank.  Neth.  Jour.  Sea  Res.  2:556-565. 

Frank,  P.  1965.  The  biodemography  of  an  intertidal  snail 
population.  Ex;ology  46:831-844 

Gallagher,  S  B.  and  G.  K.  Reid,  1974.  Reproductive  behavior 
and  early  development  in  Littorina  scabra  angulifera  and 
Littorina  irrnrata  (Gastropoda:  Prosobranchia)  in  the  Tam- 
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Hayes,  F.  R.  1929.  Contributions  to  the  Study  of  Marine 
Gastropods.  Ill  Development,  Growth  and  Behavior  of  Lit- 
torina. Contr.  Can.  Biol..  N.S.  4:413-430 

Kensler,  C.  B  1967.  Desiccation  resistance  of  intertidal  crevice 
species  as  a  factor  in  their  zonation.  Joum.  Animal  Ecol. 

Lenderking,  R.  E.   1954.  Some  recent  observations  on  the 

biology   of  Littorina   angulifera   Lam.   of  Biscajtie   and 

Virginia   Kej-s,   Florida.   Bull.   Mar  Sci.   Gulf  &   Carib. 

Merkel.  R.  D.  1971.  Temperature  relations  in  two  species  of 

West  American  Littorines.  Ecolog>- 52:1126-1130 
Moore,  H.  B.  1937.  The  biology  of  Littorina  littorea  Part  I. 

Growth  of  the  shell  and  tissues,  spawning,  length  of  life  and 

mortality.  Jour  Mar  Biol.  Assoc.  UK  21:721-742 
Palant.  B.  and  L.  Rshelson.  1968.  Littorina  punctata  (Gmelin) 

and  Littorina  neritoides  (L)  (Mollusca:  Gastropoda)  from 

Israel:  Ecology  and  annual  cycle  of  the  genital  s>'stem. 

Isreal  Joum.  Zool.  17:14.5-160 
Rosewater,  J.  1963.  Problems  in  species  analogues  in  world 

Littorinidae.  >lmer.  MalacoL  Union,  Ann.  Reps..  Bull  30:5-6 
Simon,  J.  L.  1974.  Tampa  Bay  estuarine  system  -  a  s>Tiopsis. 

Flo.  Sci.  37:217-244 
Smith,  J.  E.  and  G.  E.  Newell.  1954.  The  dynamics  of  the 

zonation  of  the  common  periwinkle  Littorina  littorea  (L)  on 

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intertidal  mollusks.  Ecology  53:693-700 


Arthur  H.  Qarke 

Smithsonian  Institution 
Washington,  D.C.  20560 

Analysis  of  field  data  associated  mth  35  species  of  boreal  and  arctic  North 
American  Sphaeriidae  indicates  interesting  correlations  between  species  oc- 
currences and  types  of  lentic  habitats.  A  few  species  combine  the  attnbutes  of 
stenotopy,  broad  geographical  distribution,  relative  abundance  and  relative  ease  of 
taxonomic  identification  and  appear  to  be  of  use  as  trophic  lake  stage  indicators. 
These  are:  Pisidium  conventus  Qessin  and  Sphaerium  nitidum  Gessin  for 
oligotrophic  lakes,  P.  idahoense  Roper  and  S.  striatinum  (Lamarck)  for 
mesotrophic  lakes,  and  P.  rotundatum  Prime  and  S.  simile  (Say)  for  eutrophic 

Tlie  characterization  of  inland  aquatic  en- 
vironments based  on  mollusks  frequently  con- 
stitutes an  integral  part  of  Quaternary 
paleoecological  studies  (Camp,  1974;  Gibson,  1967; 
Miller.  1966;  Taylor,  1957;  and  Warner,  1968).  In 
such  studies  the  whole  biological  assemblage  pre- 
sent (often  consisting  of  pollen,  ostracod  shells, 
mollusk  shells,  and  fish  bones)  or  the  mollusk 

assemblage  alone  (consisting  of  gastropod  and 
sphaeriid  shells  and  possibly  also  of  freshwater 
mussel  shells)  may  be  analyzed  and  evaluated. 
The  use  of  only  a  few  critical  species  of 
Sphaeriidae  for  interpretation  of  paleoen- 
vironments,  or  for  characterization  of  existing 
trophic  lake  stages,  has  not  been  attempted,  at 
least  in  North  America. 

Vol.94  (4) 

October  30, 1979 


The  Sphaeriidae  (also  known  as  Pisidiidae) 
(Superfamily  Corbiculacea)  are  a  large  worldwide 
family  of  small  freshwater,  bivalved  mollusks. 
Unlike  the  other  native  families  of  freshwater 
clams  (Superfamily  Unionacea)  the  shells  are 
small  (15  mm  or  less  in  most  species), 
porcelaneous,  and  have  lateral  teeth  both  anterior 
and  posterior  to  the  cardinal  teeth.  The  life 
histories  of  the  North  American  species  have 
been  described  by  Heard  (1965, 1977). 

A  preliminary'  summary  of  information  con- 
cerning the  relative  abundance,  regional  geo- 
graphical distribution,  and  kinds  of  aquatic 
habitats  occupied  by  the  sphaeriids  of  northern 
North  America  is  presented  in  Table  1.  The 
species  list  is  believed  to  be  complete  for  Canada. 
With  the  exception  of  two  warm -temperate 
species  in  the  southeastern  United  States  (Eupera 
cubensis  (Prime)  and  Pisidium  punctifeiitm  (Gup- 
py))  and  one.  rare,  relict  species  in  northern 
California  and  southern  Or^on  (P.  ultramon- 
tanum  Prime),  the  list  is  also  believed  to  be  com- 
plete for  the  continental  United  States.  Relative 
abundance  estimates,  distribution  approxima- 
tions, and  habitat  identifications  refer  only  to 
populations  in  Canada  and  northern  United 
States.  The  abbreviations  under  Distribution 
refer  to  ph>togeographic  regions  (see  brief  sum- 
mary in  Qarke,  1973). 

Inspection  of  the  table  reveals  that  most 
species  are  eur>topic,  or  wide-ranging  in  habitat 
preferences.  Among  those  which  are  common  and 
widely  distributed,  only  a  few  are  principally 
associated  with  lakes  in  any  one  particular  stage 
of  trophic  development.  These  are,  for 
oligotrophic  lakes:  Pisidium  conventus  and 
Sphaerium  nitMum:  for  mesotrophic  lakes:  P. 
idahoense  and  S.  striatinum:  and  for  eutrophic 
lakes:  P.  rntimdatum  and  5.  simile.  S.  occidentale 
(uncommon  in  Canada  but  locally  common  in  the 
United  States)  is  characteristic  of  the  most  ad- 
vanced aquatic  stage  in  lake  development,  i.e. 
swamps  and  temporary  (vernal)  ponds  and  pools. 

-wilful  UTih 

t  .«nlHul  (oiih 




\  ^  fWnixucTbunl 




FIG.  1.  Parts  of  a  sphaeriid  shell  (Pisidium  idahoense  Roper 
left  and  right  valves  from  different  specimens),  semidiagram- 

The  following  short  descriptions  and  the  il- 
lustrations are  designed  to  assist'  limnologists 
who  are  unfamiliar  with  the  Sphaeriidae  but  who 
wish  to  be  able  to  identify  the  indicator  species 
here  selected.  The  structural  terms  used  are 
defined  in  Figure  1  and  the  species  are  il- 
lustrated in  Fig.  2  and  3.  The  beaks  (umbones) 
are  located  dorsally  and  near  the  posterior  end  in 
most  species  of  Pisidium.  In  species  of  sphaeriids 
which  have  the  beaks  more  centrally  located,  the 
anterior  and  posterior  of  empty  shells  can  be 
found  by  examination  of  the  hinge  teeth.  The 
right  valve  bears  a  single,  very  small  cardinal 
tooth  located  under  the  beak  and  4  (2  pairs)  of 
narrow,  elongate  lateral  teeth,  one  pair  located 
on  either  side  of  the  cardinals.  The  left  valve 
bears  2  cardinals  and  2  single  laterals  which  ar- 
ticulate with  the  corresponding  teeth  in  the  right 
valve.  In  life  the  animal  moves  forward  with  the 
beaks  held  upward,  the  right  valve  on  the  right 
and  the  left  valve  on  the  left.  The  most  elevated 
part  of  each  lateral  tooth  is  the  cusp.  The  posi- 
tion is  proximal  if  it  is  close  to  the  cardinal  teeth 
(or  tooth)  and  distal  if  it  is  far  from  them. 

The  user  is  cautioned  that  positive  identifica- 
tion   of    sphaeriid    species    is    often    difficult, 

TABLE    1 


Relative  Abunda 
Habitats  of   the  Sph^ 

nee.    Approximate  Distributions,    and  Usual 
Sphaeriidae   of  northern  North  America^^^ 

Abbreviations.      Abundance:    C,    abundant   or  common;    R,    uncommon  or  rare;    I,    recently 
introduced    (relative   abundance   unstable).      Distribution;   A,    arctic;    T,    arctic-boreal 
transition   zone;    B,   boreal    forest;    M,   western   montane   region;   P,   prairie  and  parkland 
region;    G,   Great  Lakes-St.    Lawrence    forest   region.      Habitat:    X,    frequent  occurrence; 
X,    infrequent  occurrence. 


October  30, 1979 

Vol.94  (4) 







W   of   95° 

E  of  95° 





Plsidlum  waldeni   Kuiper 


A  T 

X   X   X   X 


P.    conventus  Clessin 


A   T   B   M 

A   T   B   C 

X   X   X   X 


Sphaerlum  nitidum  Clessin 


A   T    B   M 

A  T    B   C 

X   X    X   X 



P.    compressum   Prime 


T    B   M   P 

T   B   C    IX   X   X   X 



P.    lilljeborgi    Clessin 


A    T    B   M   P 

A  T   B   R 

X    X   X   X 



P.    nitidum  Jenyns 


A   T   R   M   P 

T   B   C 

X   X   X   X 



P.    subtruncatum  Malm 


A   T    B  M   P 

B   C 

XXXX     IX   XXX 


P.    casertanum   (Poll) 


T    B   M   P 

T   B   C 

X   X   X   X 




P.    idahoense   Roper 


A   T   B   M 

B  r. 




P.    fallax  Sterki 


B        P 

B   R 




S.    striatinum   (Lamarck) 


T   B   M   P 

T   B   G 



S.    comeum    (I.) 





P.    amnicum   (Mil Her) 





P.    ferrugineum  Prime 


A  T   B   M   P 

A   T   B    R 



P.    henslowanum    (Sheppard) 





P.    supinum  Schmidt 





P.    variabile    Prime 


T   B   M 

T   B   G 



P.    ventricosum   Prime 


T   B   M 

T   B   C 



P.    walkerl    Sterki 


A   T   B   M 

T   B   G 



S,    transversum    (Say) 



B   G 

X   X   X   X 

X   X   X   X 


P.    adamsi   Prime 


B        P 

B   G 



P.    mi  1 lum  Held 



T   B   C 



S.    lacustre    (Muller) 


T    B   M  P 

T   B   R 



P.    cruciatum   Sterki 




P.    dubium    (Say) 




P.    equilaterale   Prime 


B  G 


P.    punctatum  Sterki 


B   M 

B   G 


P.    rotuindatum  Prime 



T    B  G 


S.    patella    (Gould) 




S.    rhomboideum   (Say) 


B   M 

T   B   G 


S.    simile    (Say) 


B   G 


S.    partumelum    (Say) 


B        P 

B   G 



S.    securis   Prime 



B   G 



S.    occldentale   Prime 
P.    Insigne   Cabb 
S.    fabale   Prime 



T    B    R 

/ 1 


\    _    _    _    _ 




-    -    -     llOLic    only/     -------- 

i  ^  .^  f   1   ^       nnlitl        ^       .•      ^       ^       -M      —       ^      ^ 

—   —  —    Miotic   oniy^    _   -  —   - 

Vol.94  (4) 

October  30, 1979 


especially  in  Pisidium.  Even  though  the  eight  in- 
dicator species  are  among  the  easiest  to  identify, 
for  verification  one  should  refer  to  Herrington 
(1963),  Burch  (1972),  Clarke  (1973,  1979).  or  better 
still,  to  all  of  these.  5.  simile  and  5.  striatinutn 
are  the  most  abundant  species  of  Sphaerium  and 
are  the  most  frequently  encountered,  but  in 
Pisidium  the  most  abundant  is  the  variable 
species  P.  casertanum  (Poll)  followed  by  P.  com- 
pressum  Prime  and  several  other  species. 

Sphaetium  nitidum  (Clessin)  (Figs.  2,  J-M)  is 
up  to  6  mm  long,  rounded  anteriorly,  posteriorly, 
and  ventrally,  and  with  centrally-located  beaks. 
Fine  concentric  striae  (more  than  12  per  mm) 
cover  the  shell  and  maintain  their  height  and 
spacing  up  over  the  beaks.  There  is  no  radial 

ridge  on  the  inside  of  the  shell.  The  periostracum 
is  shiny  and  pale  yellowish-brown. 

Sphaerium  occidentale  Prime  (Figs.  2,  N-Q)  is 
up  to  7  mm  long,  also  rounded  anteriorly, 
posteriorly,  and  ventrally  and  with  centrally- 
located  beaks.  The  fine  concentric  striae  (more 
than  12  per  mm)  which  cover  the  shell  are  even 
finer  near  and  over  the  beaks.  A  low,  flat,  radial 
ridge  on  the  inside  of  the  shell  runs  from  the 
beak  cavity  to  the  central  ventral  margin.  The 
periostracum  is  pale  yellowish-brown  to  brown 
and  dull  or  somewhat  glossy. 

Sphaerium  simile  Say  (Figs.  3,  G-J),  the  largest 
Sphaerium  in  North  America,  ordinarily  exceeds 
16  mm  in  length  and  may  reach  25  mm.  The  shell 
is   long  oval,   rather  thin   to   fairly   thick,   and 


FIG.  2.  Trophic  lake-stage  indicator  species  of  Sphaeriidae.  A-C,  Pisidium  rotundatum  (USNM  595777,  length  1.95  mm);  D-H, 
Pisidium  ventricosum  (USNM  16U25.  1.85  mm):  J-M,  Sphaerium  nitidum  (USNM  216222.  S.i5  mm):  N-Q,  Sphaerium  occidentale 
(USNM iTiS.J2.  7.55  mm). 


October  30, 1979 

Vol.  94  (4) 

FIG.  3.  TVnphic  lake-stage  indicator  species  of  Sphaeriidae.  A-C,  Sphaerium  striatinum  (NMC  502S0.  length  13.0  mm):  D-F, 
Pisidium  idahoense  (NMC  327J,8.  7.1  mm):  G-J,  Sphaerium  simile  (NMC  1,5082,  118  tnm):  K-P,  Pisidium  conventus  (USNM 
363001.  3.0  mm). 

Vol.  94  (4) 

October  30, 1979 


covered  with  coarse  concentric  striae  (8  or  fewer 
per  mm  near  the  center)  which  are  more  widely 
spaced  over  the  beaks.  The  periostracum  is 
brownish  or  yellowish,  with  concentric  lighter 
and  darker  bands,  and  the  interior  of  the  shell  is 

Sphaerium  stiiatinum  (Lamarck)  (Figs.  3,  A-C) 
is  up  to  14  mm  in  length,  oval,  and  relatively 
thick  and  strong.  It  is  covered  by  concentric 
striae  (8  or  less  per  mm)  which  are  unevenly 
spaced  and  irregularly  strong  or  weak  in  the 
same  specimen,  but  are  not  weaker  on  the  beaks. 
It  is  also  brownish  or  yellowish,  with  concentric 
darker  and  lighter  bands,  and  with  a  bluish  in- 
terior. In  juveniles,  the  dorsal  margin  is  curved 
in  5.  striatinum  but  straight  in  S.  simile. 

Pisidium  conventus  Clessin  (Figs.  3,  K-P)  is 
small  (less  than  3  mm  long),  variable  in  shape 
(ordinarily  some  specimens  are  trapezoidal),  thin, 
fragile,  suboval,  not  inflated,  and  with  a  dull 
glossy  periostracum.  The  hinge  plate  is  long 
(more  than  3/4  the  shell  length),  with  cardinal 
teeth  overhanging  the  edge  of  the  hinge  plate, 
and  with  lateral  teeth  thin  and  narrow  and  with 
the  cusps  (the  highest  parts)  located  near  the 
outer  ends.  For  further  details  see  Heard,  1963. 

Pisidium  idahoense  Roper  (Figs.  3,  D-F)  is 
large  (for  Pisidium),  up  to  12  mm  long,  but  most 
specimens  are  closer  to  8  mm.  The  shell  is  ovate, 
with  a  short  dorsal  margin,  and  with  the  surface 
covered  by  fine,  concentric  striae  (15  or  more  per 
mm).  These  characters  will  distinguish  P.  ida- 
hoense from  the  other  large  species  of  Pisidium 
(P.  adamsi,  P.  amnicum,  and  P.  dubium).  Al- 
though P.  idahoense  is  characteristic  of  meso- 
trophic  lakes  throughout  its  range  on  the  North 
American  mainland,  it  occurs  in  eutrophic  lakes 
on  Prince  Edward  Island,  Canada. 

Pisidium  rotundatum  Prime  (Figs.  2,  A-C)  (and 
P.  ventricosum  Prime,  Figs.  2,  D-H)  are  both 
small  (about  3  mm  long)  and  more  spherical  in 
shape  than  most  other  Pisidium  species.  In  P. 
rotundatum  the  height  divided  by  the  length 
(H/L)  is  .80  to  .92  and  the  width  divided  by  the 
length  (W/L)  is  .70  to  .76.  In  P.  ventncosum 
(H/L)  is  .82  to  1.00  and  (W/L)  is  .80  to  .95.  In  P. 
rotundatum.  the  beaks  are  located  almost  central- 
ly or  are  posterior  of  center  but  in  P.  ven- 
tncosum they  are  far  posterior.  In  the  left  valve 
of  P.  rotundatum  the  hinge  plate  between  the 

cardinal  teeth  and  the  anterior  lateral  tooth  is 
narrow  and  much  longer  than  wide,  whereas  in 
P.  ventricosum  it  is  thick  and  short,  i.e.  about 
equally  long  and  wide.  P.  rotundatum  is 
characteristic  of  eutrophic  water  bodies  and  P. 
ventricosum  occurs  in  both  mesotrophic  and 
eutrophic  lakes. 

It  is  useful  to  remember  that  some  small 
marine  bivalve  mollusks  resemble  sphaeriids  and 
may  be  mistaken  for  them,  and  vice  versa.  This  is 
especially  important  in  the  interpretation  of 
fossil  deposits.  The  various  species  of  marine 
bivalves  all  possess  unique  hinge  teeth  and  other 
differential  characteristics,  however,  which  can  be 
observed  by  careful  examination.  See  Abbott 
(1974)  and  included  references  for  further  in- 
formation on  marine  mollusks. 

It  should  be  remembered  that  occasional 
specimens  of  most  sphaeriid  species  may  be  found 
in  all  kinds  of  habitats.  The  presence  of  an  in- 
dicator species  is  therefore  only  significant  as  a 
trophic  lake-stage  indicator  if  that  species  occurs 
in  relative  abundance. 

As  one  gains  familiarity  with  Sphaeriidae,  in- 
terpretation of  trophic  lake  stages  based  on  them 
becomes  more  practical.  The  shells  of  most  species 
are  variable,  however,  and  the  significant 
characteristics  of  the  hinge  teeth  of  Pisidium  are 
minute  and  difficult  to  observe.  It  is  therefore 
recommended  that  limnologists  utilize  for  lake 
classification  a  larger  suite  of  indicator  species 
than  that  provided  by  the  Sphaeriidae  alone. 

I  thank  C.  0.  Berg,  G.  L.  Mackie,  and  J. 
Rosewater  for  useful  suggestions,  Ms.  Cathy 
Lamb  for  laboratory  assistance,  and  Mrs.  Carolyn 
Gast  for  preparing  the  drawings.  The  photographs 
were  supplied  through  the  courtesy  of  the  Na- 
tional Museums  of  Canada  and  the  Smithsonian 


Abbott.  R.  T.  1974.  American  Seashells.  Second  Edition.  Van 
Nostrand  Reinhold  Company,  New  York.  663  pages. 

Burch.  J.  B.  1972.  Freshwater  Sphaeriacean  Clams 
(Mollusca:Pelecypoda)  of  North  America.  Biota  of 
Freshwater  Ecosystems  Identification  Manual  No.  3.  pp.  i- 
viii  +  1-33.  United  States  Government  Printing  Office, 

Camp,  M.  J.  1974.  Pleistocene  Mollusca  of  three  southeastern 
Michigan  marl  deposits.  Sterkiana  No.  56:21-64. 


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Clarke,  A.  H.  1973.  The  freshwater  molluscs  of  the  Canadian 

Interior  Basin.  Malarologia  13:l-.509. 
.    (1980):    The    Freshwater    Molluscs   of   Canada 

Special  Publications,  National  Museums  of  Canada,  Ottawa 

(in  press). 
Gibson,  G.  G.  1967.  Pleistocene  non-marine  MoUusca  of  the 

Richardson    Lake   deposit,   Clarendon   TowTiship,   Pontiac 

County,  Quebec,  Canada.  Sterkiana,  No.  25: 1-36. 
Heard,  W.  H.   1963.  The  biolog>'  of  Pisidium  (Neopisidium) 

conventus  Qessin  (Pelecypoda:Sphaeriidae).  Papers  uf  the 

Michigan  Academy  of  Science.  Art^.  and  Letters  i8:ll-S6. 
.    1965.    Comparative    life    histories    of    North 

American    pill   clams   (Sphaeriidae:ffeMf iwm).   Malacologia 


.  1977.  Reproduction  of  fingernail  clams  (Sphaeri- 

idae :Sp/iaenum  and  Mitsadium).  Malacologia  16(2):42M55. 

HerrinRtcm,  H.  B.  1962.  A  revision  of  the  Sphaeriidae  of 
North  America  (Mollusca:Pelecypoda).  Miscellaneaus 
Publicatiiins,  Museum  of  Zoology,  University  of  Michigan, 
118: 1-74, 7  plates. 

Miller,  Barry  B.  1966.  Five  Illinoian  molluscan  faunas  from 
the -southern  Great  Plains.  .Vfo/ofo/of/ia  4  (l)L173-260. 

Taylor,  D.  W.  1957.  Pliocene  freshwater  moUusks  from  Nava- 
jo County.  Arizona.  Jimmal  of  Rdeontology  31(3):654-661. 

Warner.  D.  J.  1968.  Pleistocene  Gastropoda  of  a  lake  deposit, 
Rimouski  County.  Quebec,  Canada.  Sterkiana.  No.  31:1-14. 


A.  Omura  W.  K.  Emerson  T.  L.  Ku 

Department  of  E^arth  Sciences  Department  of  Invertebrates  Department  of  Geological  Sciences 

Kanazawa  University  American  Museum  of  Natural  History  Universityof  Southern  California 
Kanazawa  920,  Japan                       New  York,  NY  10024  Los  Angeles.  CA  90007 


Nine  ""Th/^'^U  and  "^Pa/^^^U  dates  on  six  coexisting  corals  (Porites  califor- 
nica)  and  echinoids  (Encope  grandis)  from  the  Magdalena  Terrace,  west  coast  of 
Baja  California  Sur,  Mexico,  average  116,50O±6,0O0  years  (±  one  standard  devia- 
tion). Based  on  this  average,  the  newly  named  Magdalena  Terrace  may  he  cor- 
relative with  the  Nestor  Terrace  in  the  San  Diego,  California  area  and  possibly 
with  several  other  late  Pleistocene  terraces  along  the  California  coast  thought  to 
have  been  formed  during  a  highstand  of  the  sea  120,000  -  125,000  years  ago. 
Although  fossil  echinoids  contain  uranium  of  secondary  origin  their  ages  are  con- 
cordant with  those  of  the  coexisting  corals  and  suggest  that  the  uranium  uptake 
occurred  .^oon  after  the  death  of  the  organisms.  77!?.s.  as  well  as  the  low  "^Tli  con- 
tent in  both  the  living  and  fossil  Encope  analyzed  suggests  that  a  further  in- 
vestigation of  echinoids  is  warranted  to  examine  their  suitability  .for 
geochronological  studies  with  U-series  nwclides. 

We  report  the  ""Th/"''U  and  "■Pa/"'U  dating 
on  two  samples  of  the  stony  coral  Porites  califor- 
nicn  and  four  samples  of  the  irregular  echinoid 
Encope  grandis  from  marine  terrace  sediments  at 
Magdalena  Bay  (Bahia  Magdalena)  on  the  west 
coast  of  Baja  California  Sur.  Mexico.  The  mean 
and  standard  deviation  of  the  six  "°Th/'^''U  dates 
are  117,000  ±  7,000  years.  The  mean  and  standard 
deviation  of  the  three  "'Pa/"'U  dates  are 
115,000  ±  5,000.  The  two  methods  are  in  con- 

cordance, giving  an  average  age  for  the  nine 
dates  on  the  six  samples  as  116,500  ±  6,(X)fl  years. 
U-series  dates  exist  for  several  terraces  bordering 
southern  California  (summary  in  Ku  and  Kern, 
1974)  and  from  Guadalupe  Island  (Isla  Guada- 
lupe), some  400  km  off  Baja  California  Norte 
(Goldberg.  1965).  Our  dates  are  the  first  for 
Pleistocene  terrace  sediments  from  penisular  Baja 
California.  TVie  radiometric  dates  now  available 
for  the  richly  fossiliferous  deposits  of  Magdalena 

Vol.  94  (4) 

October  30, 1979 


Ba.\'  permit  more  precise  regional  comparisons  of 
this  fauna  with  those  of  chronologically  related 
Pleistocene  deposits  dated  previously. 

The  present  results  suggest  that  Pleistocene 
specimens  of  echinoids,  and  possibly  those  of 
other  echinodeiTns,  are  potentially  datable  by  the 
U-series  methods.  This  is  significant  in  view  of 
the  general  scarcity  of  specimens  of  coral  in  ter- 
race deposits.  Echinoids,  especially  the  disarticu- 
lated plates  and  spines  of  regular  ones  (sea 
urchins)  and,  to  a  lesser  degree,  the  tests  of  ir- 
regular ones  (sand  dollare)  are  not  uncommonly 
pi'eserved  in  terrace  sediments.  If  reliable 
radiometric  dates  can  be  obtained  from  echinoids, 
the  numerous  terrace  deposits  of  late  Pleistocene 
age  along  the  West  American  borderland  and 
elsewhere  throughout  the  world  can  be  dated 
more  precisely. 

1841,  were  collected  from  a  Pleistocene  terrace 
about  1.5  km  north  of  the  village  of  Puerto 
Magdalena  (24°38'N,  112°09'W),  on  the  east  side 
of  Santa  Magdalena  peninsula,  Baja  California 
Sur,  Mexico,  from  The  American  Museum  of 
Natural  History  [A.M.N.H.]  locality  F-6 
[  =  California  Academy  of  Sciences  (C.A.S.)  locali- 
ty 754];  see  Figure  1.  The  samples  analyzed  with 
U.S.C.  lab.  nos.  designated  as  AO-3,  -4,  -5  (Table 
1)  are  from  A.M.N.H.  locality  F-6  collected  on 
March  17,  1957  (Emerson,  1958).  Those  designated 
as  AO-6,  -7,  -8  (Table  1)  are  from  C.A.S.  locality 
754,  collected  July  25.  1925  by  G  D.  Hanna  and  E. 
K.  Jordan  (Jordan,  1936). 

The  two  Recent  specimens  (U.S.C.  lab.  no. 
AO-1,  -2)  of  Encope  grandis  are  from  San  Carlos 
Bay,  near  Guaymas,  Sonora,  Mexico  (27°57'N, 


The  coexistent  fossil  specimens,  comprising  of 
two  samples  of  Pontes  califomka  Verrill,  1870 
and  four  samples  of  Encope  grandis  L.  Agassiz, 

Table     1    summarizes    analytical     results    of 
samples  AO-1  through  AO-8.  Known  quantities  of 

Table  1.  Radiometric  and  Age  Data  on  Echinoids  and  Corals  from  Mexico 



1'    Mineralogy 





"'Pa  5 

Age  (10= 


























Aragoni te 









-1  9 




























































Encope  grandis;  P 

.c:  Por 

-ites  cal 


Recent,  dead-collected,  beach  specimen. 
Recent,  live-collected  specimen. 
Pleistocene  specimens, 
n.m.  :  not  measured. 


October  30,1979 

Vol.  94  (4) 

232  U_  228'J^    ^j^(J    233p^    ^,g^p   ^gg^J  ^g  y\^\^   traCCfS   Ih 

the  analyses  of  the  radioisotopes  listed.  The 
quoted  errors  (one  standard  deviation)  are  based 
on  the  counting  statistical  fluctuations  only. 
Mineralogical  identifications  were  done  with 
x-ray  diffraction  techniques.  In  computing 
the  ages,  we  assumed  that  "°Th  and  "'Pa  were 
initially  absent  or  present  in  negligible  amounts 
and  that  samples  acted  as  a  closed  system  after 
incorporation  of  the  radioisotopes.  The  half-life 
values  used  for  ""Th  and  "'Pa  are  75,200  years 
and  34,300  years,  respectively. 

The  assumption  of  negligible  initial  ""Th  and 
"'Pa  (Table  1)  is  suppf)rted  by  the  observations 
that,  firstly,  "'•Th/"'Th  values  in  the  fossil 
specimens  are  very  much  higher  than  those 
values  in  natural  waters  or  sediments,  which  are 
commonly  1  to  3,  and  secondly,  modern  specimens 
of  E.  yrandis  show  very  low  ^^°Th/"''U  and 
"'Pa/"*U  values  of  <0.1,  as  is  the  case  for  corals 
(Ku,  1968).  The  closed-system  assumption  is  sup- 
ported by  the  concordancy  checks  between  the 
"°Th/"^U-  and  "'Pa/"'U-"  derived  ages  on  three 
samples  in  which  such  checks  were  made  (Table 
1).  The  validity  of  this  assumption  is  alscj 
reflected  in  the  agreement,  within  counting 
statistical  error,  of  ages  for  the  six  coexisting 
fossil  specimens. 

As  the  present  study  reports  the  first  mea- 
surements on  echinoids,  a  discussion  of  the  data 
obtained  is  in  order.  The  ""U/"'  U  ratios  of  1.14 
in  AO-1  and  AO-2  are  the  same  as  that  for 
uranium  in  sea  water  (Ku,  et  ai,  1977).  Living  E. 
'(innidis  apparently  incorporate  about  0.2-0.3  ppm 
of  uranium  directly  from  sea  water.  Unlike  coral, 
there  appears  to  be  a  discrimination  factor  of  10 
to  1  in  favor  of  Ca  to  U  in  the  uptake  of  these 
two  elements  from  sea  water  by  the  organism. 
With  the  exception  of  the  echinoderm  teeth,  the 
hard  tissue  of  echinoderms  is  known  to  be 
originally  composed  of  calcite  containing  several 
per  cent  Mg  (Chave,  1954;  Schroeder  et  al.,  1969). 
This  is  the  case  for  samples  AO-1,  -2,  and  -4. 
Because  high-Mg  calcite  is  metastable  under  sur- 
face conditions,  its  transformation  to  low-Mg 
calcite  could  provide  conditions  condusive  to  ex- 
change of  radionuclides  with  thase  in  the 
surroundings— conditions  similar  to  the  conver- 
sion from  aragonite  to  calcite  for  coral.  Data  on 
samples  AO-5,  -7.  and  -8  suggest  that  during  the 

transformation  to  low-Mg  calcite,  significant 
amounts  of  uranium  may  have  entered  the 
echinoid  skeletal  tests  with  little  or  no  accompa- 
nying thorium  isotopes.  For  sample  AO-4,  the 
slightly  higher-than-modem  U  value  (ppm)  fur- 
ther suggests  that  limited  addition  of  uranium 
could  have  also  occurred  before  the  transforma- 
tion. This  secondary  uranium  added  to  the  sam- 
ple is  largely  of  non-marine  origin,  judging  from 
the  "''U/"«U  value  of  1.01  ±  .02  (oceanic  uranium 
would  decay  from  1.14  to  1.10  in  about  120,tKX) 

From  the  above  discussion,  one  sees  some 
parallel  between  E.  gy-andis  and  mollusks  in 
terms  of  open  system  for  secondary  uranium  up- 
take in  fossil  specimens.  However,  the  present 
results  show  two  encouraging  aspects  of  dating  E. 
grandvi:  (1)  The  concordant  ages  obtained  here 
suggest  that  the  open-system  episode  must  have 
been  brief  and  limited  to  a  period  very  close  to 
the  death  of  the  organism.  (2)  There  is  evidence 
for  n^ligible  presence  of  initial  and  extraneous 
"°Th  and  "'Pa  in  the  samples  analyzed  (Table  1). 
These  favorable  conditions  have  been  found  in 
mollusks,  but  they  are  not  common  (Kaufman,  et 
al.,  1971).  Thus  for  echinoids,  one  needs  to  deter- 
mine how  commonly  these  conditions  occur  and 
what  criteria  are  required  to  distinguish  them. 
These  questions  cannot  be  answered  from  the  pre- 
sent limited  number  of  analyses.  Further  studies 
of  echinoid  tests  to  evaluate  their  suitability  for 
U-series  dating  are  warranted. 




The  terrace  represented  by  A.M.N. R  locality 
F-6  (Fig.  1)  extends  along  the  shore  at  a  max- 
imum elevation  of  approximately  6  meters  above 
sea  level.  The  fossils  are  most  numerous  in 
sediments  of  poorly  sorted  sand  and  angular  ig- 
neous rocks  exposed  along  the  shore  at  the  high 
tide  level  to  an  elevation  of  1.5  to  1.8  meters.  The 
fossiliferous  sand  is  locally  overlain  by  0  to  4.6 
meters  of  non-fossiliferous  alluvial  cover.  A  con- 
glomerate resting  on  the  terrace  platform,  which 
cuts  into  the  basal  igneous  bench-rock,  is  exposed 
at  the  level  of  the  present  beach  on  the  apparent- 
ly correlative  terrace  remnants  that  are  pre- 
served along  the  shore  for  about  1.5  km  south  of 

Vol.  94  (4) 

October  30, 1979 


AREA  OF  . 

IHOtX  MAP    \^  N 

FIG.  1.  Iiidei-  map  afthe  Magdalena  Bay  -  Almejiui  Bay  area  ofBnja  California  Sur.  Mexico,  showing  Pleistocene  fossil  localities  (F-5, 
F-6  on  Santa  Magdalcna  peninifula:  F-7.  F-S  on  Santa  Margarita  Island)  described  in  the  text. 

Puerto  Magdalena  village  (Figure  1,  A.M.N.H. 
locality  F-5  =  C.A.S.  locality  982).  This  con- 
glomerate and  the  terrace  platform  are  not  ex- 
posed at  locality  F-6.  According  to  Hanna  (1925), 
these  terrace  remnants  represent  the  beach-line 
existing  at  the  time  of  uplift  of  the  igneous  and 
metamorphic  rocks  which  form  the  higher  terrain 
behind  the  village,  and  this  tectonic  event  re- 
sulted in  the  closure  of  the  northern  entrance 
to  Magdalena  Bay.  A  terrace  similar  to  that  at 
Puerto  Magdalena  is  exposed  north  and  south  of 
the  village  of  Puerto  Cortes  on  the  eastern  shore 
of  adjacent  Santa  Margarita  Island  (Isla  Santa 
Margarita),  which  faces  Almejas  Bay  (Bahia 
Almejas),  see  Figure  1.  This  terrace  extends 
about  6.5  km  along  the  shore  south  of  Puerto 
Cortes  at  a  maximum  elevation  of  about  4.6  m  (at 
A.M.N.H.  locality  F-7)  and  continues  north  of  the 
village  at  the  same  height  for  about  1.2  km 
(Figure  1,  A.M.N.H.  locality  F-8=C.A.&  locality 
932).  The  terraces  exposed  at  the  localities  on 
Santa  Margarita  Island  are  cut  into  basal  igneous 

rocks  (0-1.5  m  in  thickness)  and  are  overlain  by 
conglomerates  (.5  to  6  m),  fossiliferous  sand  peb- 
bles (.5  to  1.2  m),  and  pebbly  soil  cover  (.5  and  1.2 
m).  The  terrace  appears  to  be  tilted  slightly  to 
the  northwest,  as  is  the  terrace  on  the  Santa 
Magdalena  peninsula.  These  topographic  features 
are  here  designated  the  Magdalena  Terrace,  with 
the  type  locality  restricted  to  the  section  exposed 
at  A.M.N.H.  locality  F-6  on  the  Santa  Magdalena 

The  presence  of  well-preserved  metazoan  in- 
vertebrate fossils,  mostly  mollusks,  in  terrace 
sediments  in  the  vicinity  of  Magdalena  Bay  has 
long  been  known.  Hinds  (1844)  was  the  first  to 
report  mollusks  "...  embedded  in  the  fossiliferous 
cliffs  which  surround  a  portion  of  the  Bay  of 
Magdalena."  Dall  (1918),  Smith  (1919),  Jordan 
(1924),  and  Hanna  (1925)  considered  the  age  of 
these  terraces  to  be  Pleistocene,  based  on  faunal 
evidence.  Jordan  (1936)  listed  a  total  of  442 
species-group  taxa,  including  4  echinoderms,  1 
coral,  and  337  mollusks,  from  three  locations  in 


October  30, 1979 

Vol.  94  (4) 

Magdalena  Bay  (C.A.S.  localities  754,  932,  and 
982).  He  concluded  that  "...the  beds  should  be  cor- 
related with  the  warm  Upper  San  Pedro,  or  Up- 
per Quaternary"  (of  Arnold  (1903)  in  the  Los 
Angeles  Basin,  now  referable  to  the  upper 
Pleistocene  Palos  Verdes  Sand).  The  Magdalena 
Bay  assemblage  is  the  largest  Pleistocene  in- 
vertebrate fauna  described  from  Pacific  Baja 
California  (Emerson,  1956;  Gastil  et  ai.,  1975) 
and,  in  western  North  America,  it  is  second  in 
size  only  to  the  assemblages  reported  from 
Newport  Bay,  California,  where  nearly  500 
species  of  metazoan  invertebrates  are  recorded 
from  late  Pleistocene  deposits  (Kanakoff  and 
Emerson,  1959). 

The  fauna!  constituents  of  the  Magdalena  Ter- 
race are  essentially  modem  in  composition,  con- 
taining a  nearly  equal  mixture  of  Panamic  and 
Califomian  Provincial  faunal  elements,  together 
with  wide-ranging,  eurytopic  taxa.  The  metazoan 
invertebrates  living  at  the  present  time  in 
Magdalena  Bay  also  represent  a  blending  of  these 
faunal  components,  with  perhaps  a  diminution  in 
the  ratio  of  the  warm  water  (Panamic  element) 
to  the  temperate  water  components  (Califomian 
element).  The  Panamic  element  is  present  in 
similar  terrace  deposits  occurring  northward 
along  the  continental  borderland.  This  southern, 
warm-water  element  diminishes  in  numbers 
rapidly  in  Pleistocene  assemblages  north  of  Viz- 
caino Peninsula  (27°50'N.,  115°5'W)  and  is  a 
minor  faunal  component  in  the  San  Diego  and  Los 
Angeles  embayments,  where  wide-ranging  and 
cooler  faunal  elements  dominate  (Emerson,  1956). 
Changes  in  the  composition  of  these  assemblages 
have  been  largely  ascribed  to  alternating 
hydroclimatic  regimes  that  accompanied  the  late 
Pleistocene  oscillations  of  the  continental  ice 
sheets  (cf.  Valentine,  1955,  1961;  Kanakoff  and 
Emerson,  1959;  Addicott  and  Emerson,  1959; 
Kennedy  et  al..  1979).  Because  species-level  ex- 
tinctions in  faunas  have  been  negligible  during 
the  late  Pleistocene  and  tectonic  changes  in  the 
coastal  configuration  have  locally  obscured  the  ef- 
fects of  eustatic  changes  in  sea  level  during  this 
period,  traditional  stratigraphic  and  paleontologic 
methods  do  not  permit  absolute  temporal  and 
regional  correlations  of  these  terraces  (cf. 
Durham  and  Allison,  1960;  Ku  and  Kern,  1974). 
The  U-series  ages  obtained  here  suggest  correla- 

tion of  the  Magdalena  Terrace  with  the  Nestor 
Terrace  in  San  Diego  and  similar  terraces  in  the 
region,  formed  during  a  highstrand  of  the  sea  ap- 
proximately 120,000  yrs.  ago  (Ku  and  Kem,  1974) 
during  the  early  Sangamon  (isotopic  stage  5e  of 
Shackleton  and  Opdyke,  1973).  More  precise  cor- 
relation must  await  absolute  dating  of  additional 
regional  deposits. 

Peter  U.  Rodda,  Chairman  of  the  Department 
of  Geology,  California  Academy  of  Sciences, 
generously  contributed  fossils  for  dating  (C.A.S. 
locality  number  754).  William  E.  Old,  Jr.  of  the 
Department  of  Invertebrates,  American  Museum 
of  Natural  History  kindly  provided  technical 
assistance  in  the  preparation  of  the  manuscript. 
We  are  indebted  to  George  L.  Kennedy,  U.  S. 
Geological  Survey,  Menlo  Park,  California  and 
Leslie  F.  Marcus,  City  University  of  New  York, 
for  critically  reading  the  manuscript.  The 
radiochemical  analyses  were  done  at  the  Univer- 
sity of  Southern  California  supported  by  National 
Science  Foundation  grant  EAR  77-13680  to  T.  L. 
Ku  and  W.  H.  Easton,  Contribution  no.  394, 
Department  of  Geological  Sciences,  University  of 
Southern  California. 

Addicott.  W.  0.  and  W.  K.  Emerson.  1959.  Late  Pleistocene 

invertebrates  from  Punta  Cabras.  Baja  California.  Mexico. 

Amer.  Mus.  Novitates.  no.  192.5. 33  p. 
Arnold,  R.   1903.  The  paleontolog>'  and  stratigraphy  of  the 

marine  Pliocene  and  Pleistocene  of  San  Pedro,  California. 

Calif  Acad.  Sci.  Mem.  3:1-419. 
("have,    K.    E.    19.54.    Aspects    of    the    biogeochemistry    of 

magnesium:  1.  Calcareous  marine  organisms.  Jour.  Geol.  62: 

Dall,  W.  H.  1918.  Pleistocene  fossils  of  Magdalena  Bay,  Lower 

California,    collected    by    Charles    Russell    Orcutt.     Tfte 

Afa?rfi7i(.s  32:23-26. 
Durhiun,  .1.  W.  and  E.  C.  Alli-son.  1960.  The  geologic  history  of 

liija  California  and   its  marine  faunas.  Systematic  Zool. 

Emerson.  W.  K.  19.56.  Pleistocene  invertebrates  from  Punta 

China,  Baja  California.  Me.xico,  with  remarks  on  the  com- 
position  of  the   Pacific  Coast    Quaternary   faun;is:    .■\mer. 

Mus.  Bull.  1I1:31.5-:M2. 
1958.  Results  of  the  Puritan  -  American  Museum 

of  Natural    History    Expedition    to   western    Mexico.    1. 

General  account.  Amer.  Mus.  Novitates  no.  1894, 25  p. 
Gastil,  R.  G.,  R.  P.  Phillips,  and  E.  C.  Allison.  197.5.  Recon- 
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Amer.  Mem.  140, 170  p. 

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Goldberg,  E.  D.  1965.  An  observation  on  marine  sedimentation 
rates  during  the  Pleistocene.  Limnol.  and  Oceanog.  Suppl.. 
10:R  125-128. 

Hanna,  G  D.  1925.  Ebcpedition  to  Guadalupe  Island.  Mexim.  in 
1922.  Prnc.  Calif.  Acad.  Sci.,  ser.  4. 14:217-275. 

Hinds,  R.  B.  1844.  (On  new  species  of  Terebra).  Proc.  Zool.  Soc. 
London,  pt.  11,  "for  1843":  149-168. 

Jordan,  E.  K.  1924.  Quaternary  and  Recent  molluscan  faunas 
of  the  west  coast  of  Lower  California.  Southern  Calif.  Acad. 
Sci.  Bull.  23:145-156. 

1936.  The  Pleistocene  fauna  of  Magdalena  Bay, 

Lower  California.  Contr.  Dept.  Geol.  Stanford  Univ.  1:103 

Kanakoff,  G.  P.  and  W.  K.  Emerson.  19.59.  Late  Pleistocene  in- 
vertebrates of  the  Newport  Bay  area,  California.  Los 
.Angeles  Co.  Mus.  Contrib.  Sci.,  no.  31:  47  p. 

Kaufman,  A.,  W.  S.  Broecker,  T.  L.  Ku.  and  D.  L.  Thurber. 
1971.  The  status  of  U-series  methods  of  mollusk  dating. 
Geochim.  Cosmochim.  Acta  35:1155-11&3. 

Kennedy,  G.  L..  K.  R.  Lajoie,  and  J.  F.  Wehmiller.  1979.  Late 
Pleistocene  and  Holocene  zoogeography.  Pacific  northwest 
coast.  Abstracts,  Cordillian  Section,  Abstracts  with  Pro- 
grams, Geol.  Soc.  Amer.  11(3):87. 

Ku,  T.  L.  1968.  Pa."'  method  of  dating  corals  from  Barbados 

Island.  Jour.  Geophys.  Research  73:2271-2276. 
Ku,  T.  L.  and  J.  P.  Kern  1974.  Uranium-series  age  of  the  up- 
per Pleistocene  Nestor  Terrace,  San  Diego,  California.  Geol. 

Soc.  Amer.  Bull  85: 1713-1716. 
Ku,  T.  L,  K.  G.  Knauss  and  G.  G.  Mathieu.  1977.  Uranium  in 

open    ocean:    Concentration    and    isotopic    concentration. 

Deep-Sea  Res.  24: 1005-1017. 
Schroeder,  J.   H..   E.   K.   Dwornik   and   J.   J.   Papike.   1969. 

Primary  proto-dolomite   in   echinoid  skeletons.  Geol.  Soc. 

Amer.  Bull.  80:1613-1616. 
Shackleton,  N.  J.  and  N.  D.  Opdyke.  1973.  Oxygen  isotope  and 

palaeomagnetic    stratigraphy    of   equatorial    Pacific    core 

V28-238:  Oxygen  isotope  temperatures  and  ice  volume  on  a 

W  and  W  year  scale.  Quat.  Res.  3:39-55. 
Smith,  J.   P.  1919.   Climatic  relations  of  the  Tertiary  and 

Quaternary  faunas  of  the  California  region:   Proc.  Calif. 

Acad.  Sci.,  ser.  4, 9: 123-17.3. 
Valentine,  J.  W.  19.55.  Upwelling  and  thermally  anomalous 

Pacific  Coast  Pleistocene  molluscan  faunas.  Amer.  Jour.  Sci. 

253:  462-474. 
.  1961.  Paleoecologic  molluscan  geography  of  the 

Californian   Pleistocene.  Univ.  Calif.   Publ.  Geol.  Sci.   34: 



Walter  E.  Klippel  and  Paul  W.  Parmalee 

Department  of  Anthropology' 
University  of  Tennessee,  Knoxville,  Tennessee  37916 


A  sui-vey  of  the  naiad  fauna  uf  Lake  Springfield  during  195S  pniduccd  nine 
species  of  freshwater  mussels.  A  second  survey  of  the  identical  collection  localities, 
conducted  in  1977.  produced  the  same  nine  species.  Patterned  quantative  changes 
in  the  fauna  were  observed.  Qualitative  changes  have  resulted  from  the  introduc- 
tion of  four  previously  unrecorded  species.  Variations  in  the  naiad  populations 
have  been  discussed  in  terms  of  observed  changes  in  other  aiiificinlly  formed  lentic 
habitats  as  well  as  unimpounded  fluvial  systems. 

Nearly  two  decades  after  the  construction  of 
Lake  Springfield  during  1935,  a  survey  of  the 
lake's  naiad  fauna  was,  conducted  and  reported 
by  the  junior  author  (Parmalee  1955).  The  lake, 
situated  in  Sangamon  County  in  central  Illinois, 
is  fed  by  Lick  and  Sugar  creeks,  has  a  surface 
area  of  17.6  km^  and  roughly  90  km  of  shoreline. 
At  the  time  of  the  1953  survey  central  Illinois 
had   suffered   several   months  of  below   average 

rainfall  and  by  October,  1953,  the  level  of  Lake 
Springfield  fell  to  an  average  (169.07  m  MSL)  1.62 
m  below  normal  pool  (170.69  m). 

The_exposed  shoreline  of  the  relatively  shallow 
lake  (X  depth  =  4.57  m)  gave  rise  to  the  survey 
of  stranded  freshwater  mussels  along  the  waters 
edge.  Nine  hundred  and  eighty-seven  specimens 
representing  nine  species  were  recovered  from  20 
different   collecting  stations   (Fig.   1).   The  area 


October  30. 1979 

Vol.94  (4) 

FIG.  1.  Lake  Springfield,  Rlinois,  shoviing  stations  where 
tuiiads  were  collected  in  195.i  and  1977. 

sampled  (4x50  yr.)  at  each  loci  was  about  167.4  m, 
(200  yr^),  bringing  the  total  area  collected  to  3346 
m^  and  providing  a  mean  density  of  .295/m^ 

Quadnda  quadnda  (Rafinesque,  1820)  occurred 
in  greatest  abundance  (48%),  followed  by  Lep- 
todea  laevissima  (Lea,  1830)— 22%,  Lasmigona 
complanata  (Barnes,  1823)— 11%,  Ligumia  riasutn 
(Say,  1817)-11%,  Anodmta  grandis  (Say,  1829)  - 
6%,  Amblema  plicata  (Say,  1817)-1%,  and 
Anodmta  imbecilis  (Say,  1829)— 1%.  Fusconaia 
flava  undata  (Barnes,  1823)— 1%  and  Arddens 
confragosnLR  (Say,  1829)— 1%  were  represented  by 
only  one  specimen  each  (Parmalee  1955:32). 

During  1976,  slightly  over  two  decades  after 
the  low  water  of  1953,  central  Illinois  was  once 
again  subjected  to  below  average  rainfall  which, 
by  early  winter,  had  left  Lake  Springfield  1.56  m 
(169.13  m  MSL)  below  normal  pool.  The  water 
level  continued  to  drop  until  February,  1977, 
when  it  finally  reached  a  low  of  168.80  m  MSL. 

By  March,  1977,  the  snow  cover  that  had 
blanketed  the  otherwise  exposed  shoreline  had 
melted,  and  during  the  next  ten  days  a  second 
survey  of  the  20  loci  collected  during  1953  was 
completed.  During  this  period  the  lake  level 
ranged  from  169.13  m  MSL  to  168.95  m  MSL  (Fig. 
2a)  and  was  an  average  169.19  m  MSL;  a  mean 
level  only  12  cm  higher  than  the  mean  level  for 

October,  1953,  when  the  initial  sun^ey  was  con- 
ducted. By  May,  1977,  the  lake  had  again  at- 
tained a  normal  pool  (Fig.  2b). 

Distances  of  50  m  were  marked  off  along  the 
waters  edge  at  18  of  the  20  stations  and  collec- 
tions of  all  shells  with  one  dimension  larger  than 
1.5  om  were  made  for  a  distance  of  4  m  back 
from  the  waters  edge.  In  two  instances  (Stations  9 
and  23)  the  areas  collected  were  extended  to  100 
m  long  by  only  2  m  wide  because  of  heavy  grass 
and  brush  cover  that  occurred  within  3  to  4  m  of 
the  waters  edge.  Both  of  these  stations  are  at  the 
headwaters  of  the  lake  where  the  water  line 
begins  to  take  on  characteristics  more  like  the 
btinks  of  Sugar  and  Lick  creeks  than  the  shore- 
line of  Lake  Springfield.  Although  the  dimensions 
(100x2  m)  differ  from  areas  established  at  the 
other  18  stations  (50x4  m),  even,'  attempt  was 
made  to  collect  the  same  amount  of  surface  area 
at  all  stations,  i.e.  200  m^.  It  should  be  noted  at 
this  point  that  the  areas  collected  during  1977 
(200  m^)  are  roughly  20  percent  larger  than  the 
areas  collected  in  1953  (200  yr^  =  167.3  m^. 

A  total  of  2177  paired  valves  were  recovered 
from  the  20  stations  during  1977.  The  area 
sampled  at  each  station  was  200  m^  bringing  the 
total  area  collected  to  4000  m^  and  providing  a 
mean  density  of  .544/m^  or  almost  twice  as  many 
specimens  per  unit  area  as  found  at  the  same  loci 
during  1953. 

Qualitative  Changes  in  the  Naiad  Fauna 

Qualitative  changes  have  occurred  in  the  lake's 
fauna  as  a  result  of  the  introduction  of  four  new 
species  (Carunndina  paira  (Barnes,  1823),  Tmn- 
rilla  truncata  Rafinesque  1820,  Obliqrmria  reflexa 
Rafinesque  1820  and  Corbinda  manilcns-is  Philip- 
pi).  There  has  also  been  an  overall  increase  in  the 
lake's  naiad  fauna  of  roughly  ten  percent  per 
unit  area  as  well  as  statistically  significant  quan- 
tative  changes  among  the  nine  original  species. 
Unfortunately  the  myriad  of  unmonitored,  inter- 
related factors  responsible  for  the  observed 
changes  cannot  be  fully  delineated  post  de  facto. 
but  there  are  some  patterned  variations  that  can 
be  discussed. 

The  nine  original  species  (1953)  constitute  1296 
of  the  total  2177  specimens  recovered  in  1977. 
When  these  primary  species  are  considered  sep- 
arately (n  =  1296),  the  naiad  density  per  unit  area 

Vol.94  (4) 

October  30, 1979 


is  only  slightly  greater  (.324/m^)  than  that  found 
during  the  first  survey  (.295/m^).  Increases  in  the 
mussel  fauna  are  restricted  to  as  few  as  seven 
stations  (i.e.  2,  5,  6,  9.  10,  12,  and  15)  situated 
along  the  main  body  of  the  lake  (Fig.  1)  where  in- 
creases per  unit  area  by  station  range  from  71 
percent  to  204  percent.  Density  was  nearly  the 
same  per  unit  area  at  station  16  (i.e.  <  2  percent 
change)  while  densities  per  unit  area  at  the  re- 
maining 12  stations  decreased  rather  markedly. 

The  upper  reaches  of  the  lake  and  the  heads  of 
many  of  the  inlets  have  undergone  considerable 
aggradation  through  siltation.  This  phenomenon 
was  readily  apparent  when  collections  were  made 
in  1977.  The  substrate  at  stations  4  and  13 
(inlets),  17,  18,  19  and  20  (upper  reaches  of  lake) 
consisted  of  poorly  consolidated  silty  clay  loams 
and  were  difficult  to  collect  without  sinking 
waist  deep  in  "muck".  Also,  the  color  of  these  ag- 
grading deposits  was  noticeably  darker  (Table 

TABLE  1.  Frexhwatfr  ninsscl.':  nrorcrrd  front  tiirntij  statians  alutui  the  expiised  shiireUiic  of  Lake  Springfield.  Iltindia.  diiriiiy 
1953  and  1977. 

O    I. 

—  a> 

1 2    '3 

■-J   tj        'op 

.3,2  2,  2:i 

?S  1^  I'S 

11  §2  i-f 

Of   O-  ^    a  ^  -rf 

.3  §     .3.2 


a  a,  « 

■ri   ■a  u 

fc  «      -J  •.» 

■-■3       ,0  a. 

!l      5 


ne,ne,se,se  of  Sec. 
12;  T15N;  R5W  (SE)* 

lOYR  5/4 








2, sw,ne  of  Sec. 
19;  T15N;  R4U  (NC) 

lOrR  4/4 







2   18 




nw,nw,se,se  of  Sec. 
14;  T15N;  R5U  (NC) 

lOVR  4/4 
















nw,ne,nw,sw  of  Sec. 
24;  T15N;  R5W  (NC) 

lOYR  3/2 
















se,ne,nw,ne  of  Sec. 
25;  TISN;  R5W  (NC) 

lOrR  4/2 
















6, sw,sw  of  Sec. 
19;  T15N;  R4W  (NC) 

lOYR  5/4 








6    11 




se,sw,sw,se  of  Sec. 
19;  T15N;  R4W  (NC) 

lOYR  4/4 






2     3 





sw,nw,nw,sw  of  Sec. 
30;  TISN;  R4W  (NC) 

lOYR  5/4 








3    23 




sw,nw,se,se  of  Sec. 
36;  nSN;  R5H  (NC) 

lOYR  3/1 












ne,nw,sw,se  of  Sec. 
35;  T15N;  R5W  (NC) 

lOTR  3/3 















se,se,nw,sw  of  Sec. 
36;  T15N;  R5U  (NC) 

lOYR  3/3 











ne,sw,se,se  of  Sec. 
35;  TISN;  R5U  (NC) 

lOYR  3/3 














sw,,ne  of  Sec. 

2;  T14N;  R5U  (NC) 

lOYR  3/1 












ne,ne,sw,nw  of  Sec. 
2;  TUN;  R5H  (C) 

lOYR  4/3 














sw,rTW,ne,nw  of  Sec. 
16;  T14N;  R5W  (C) 

lOTR  3/3 














sw,nw,nw,sw  of  Sec. 
3;  T14N;  R5U  (C) 

lOYR  3/2 














17  of  Sec. 
32;  T15N;  R5U  (C) 

lOYR  3/1 












ni5,ne,sw.sw  of  Sec. 
30;  T15N;  R5W  (C) 

lOYR  3/1 









nw,nw,nw,sw  of  Sec. 
9;  T14N;  R5W  (C) 

lOYR  3/1 










sw,5w,se,sw  of  Sec. 
34;  T15N;  R5W  (C) 

lOYR  3/2 












•Determined  from  7.5  minute  UbGS  quadrangles:  (SE)  ■  Springfield  East;  (NC)  -  New  City;  (C)  -  Chatham. 


October  30, 1979 

Vol.94  (4) 

1-lOYR  3/1,  3/2)  than  substrates  at  most  other 
stations  where  yellowish  brown  and  brown  soils 
(primarily  Hickory,  Clinton,  and  Elco  series— as 
depicted  on  advance  soil  sheets  for  Sangamon 
County)  are  eroding  from  the  former  valley  walls 
of  Sugar  Creek  (Table  1).  Aggrading  deposits 
transported  into  the  lake  from  the  nearly  black 
upland  prairie  soils  are  very  dark  gray  (lOYR 
3/1— Munsell)  to  very  dark  grayish  brown  (lOYR 
3/2)  and  consistently  produced  fewer  naiads  per 
unit  area  (X.ll/m^)  than  were  found  during  1953 
(X.32/m^).  The  relatively  undiluted  herbicides 
and/or  pesticides,  and  large  quantities  of  smoth- 
ering silt  particles  that  settle  out  when  they 
reach  the  sluggish  waters  of  the  lake  have  prob- 
ably contributed  to  this  decrease  in  primary 
naiad  density  at  these  stations. 

Quantative  changes  among  the  primary  species 
have  also  taken  place  over  the  past  two  decades. 
A  chi  square  conducted  on  the  1953  and  1977 
populations  (Table  2)  clearly  shows  that  there 
have  been  significant  quantative  changes  in  the 
naiad  fauna  (X^  =  202,  df  =  8.  p  .<  .001).  Q. 
quadrula,  A.  grandis  and  A.  imbecUis  occurred  in 
greater  frequencies  than  expected  during  1977 
while  L.  cotnplanaUi,  L.  laevissima,  A.  plicata, 
and  L.  nasuta  have  decreased.  Variation  in  oc- 
currence of  L.  complanata,  Q.  quadrula.  L. 
/aem,s('»(a,  A.  plicata  and  L.  natiuta  contribute 
the  greatest  respective  amounts  to  the  high  chi 
square  value. 

A   comparison   of  the   combined    assemblages 

TABLE  2.  Ncdad  fauna  recorded  for  Lake  Springfield  during 
195J compared  to  the  same  specien  recovered  in  1977. 

total  naiad 
fauna    (1953) 


1   naiad 

naiad  epecles 






Anblenu  plicata 






F^i.tninnm  tlni'it  midiitu 






Quadrula  quadrula 






Anodonta  grtmdie 






Anodanta  vnbecilie 






Arcidana  oonfragoBUB 






Latmigoruz  acmplanata 






Leptodsa  latvieeina 






ligumia  naeuta 










from  the  heads  of  inlets  and  upper  reaches  of  the 
lake  (i.e.  stations  4,  13,  17,  18,  19  and  20)  for  the 
1953  and  1977  populations  has  been  made  by  con- 
structing a  contingency  table  similar  to  that  in 
Table  2.  At  these  loci  A.  grandis.  A.  imbecilis  and 
L.  laevissima  occurred  in  greater  frequencies 
than  expected  during  1977  while  Q.  quadnda.  L. 
aiinplanata,  L.  nasuta  and  .4.  plicata  occurred  in 
fewer  numbers  than  expected.  Even  when  the  "no 
zero  cell'  requirement  is  fulfilled  and  .4.  plicata 
and  L.  complanata  are  excluded  (including  only 
Q.  quadrula,  A.  grandis.  A.  imbecilis.  L. 
laevis.Kim(i,  and  L.  nasuta).  a  chi  square  shows  a 
statistically  significant  difference  between  1953 
and  1977  population  (X^  =  33,  df  =  4,  p  <  .001). 

All  three  of  the  species  that  occurred  in 
greater  frequencies  than  expected  are  known  to 
be  more  tolerant  of  mud  substrates  and  lentic 
waters  than  many  of  the  species  that  occur  in  the 
lake  (Parmalee  1967:47,  48.  74).  This  observation 
tends  to  substantiate  our  previous  supposition 
that  naiad  populations  at  these  loci  are  being  in- 
fluenced by  siltation,  as  does  the  fact  that  Q. 
quadrula  recovered  from  these  areas  are  all 
mature  individuals  generally  over  five  years  of 

By  way  of  comparison  we  have  combined  the 
assemblages  at  the  seven  stations  on  the  main 
body  of  the  lake  that  showed  an  increase  mussel 
density  per  unit  area  (i.e.  Stations  2,  5,  6,  9,  10, 
12,  and  15)  between  1953  and  1977.  A  contingency 
table  shows  that  Q.  quadrula.  A.  grandis  and  .4. 
imbecilis  occur  in  greater  numbers  than  expected 
while  the  other  six  primar>'  species  occur  in  a 
lower  frequency  than  expected.  A  chi  square  on 
eight  of  the  nine  species  (excluding  A.  plicata 
since  none  was  found  during  1977)  shows  the  two 
I»pulations  to  be  significantly  different  (X^  = 
235  df  =  7:  p  <  .001).  These  species  are  the  same 
three  that  occurred  in  greater  frequencies  than 
exj^ected  when  all  20  stations  were  combined  and 
1953/1977  samples  were  compared.  A  similar  ma- 
nipulation of  mussel  counts  from  remaining  sta- 
tions, i.e.  those  with  decreased  naiad  density  but 
not  on  the  upper  reaches  of  the  lake  or  at  heads 
of  inlets,  show  changes  in  the  same  direction  that 
other  stations  on  the  main  body  of  the  lake  dis- 

Despite  the  lower  naiad  densities  at  these  sta- 
tions, Q.  quadrula,  A.  grandis  and  A.   imbecilis 

Vol.94  (4) 

October  30, 1979 


FIG.  2.  Lake  Springfield.  Illitmx  at  Station  13  shoiring  ex- 
posed svbstmte  near  the  head  of  an  inlet  during  March  1977. 
Water  level  is  at  169  in  MSL 

occur  in  greater  frequencies  than  expected  while 
the  remaining  species  occur  in  fewer  numbers 
than  would  be  expected  if  the  populations  had 
undergone  no  change  over  the  past  two  decades. 

Qualitative  Changes  in  the  Naiad  Fauna 

Four  species  of  freshwater  mussels  recovered 
during  1977  were  not  found  in  the  lake  during 
the  1953  survey.  Of  the  four  species  established 
since  1953,  C.  manilensis  was  found  in  greatest 
frequency.  It  made  up  28  percent  of  the  total 
specimens  recovered  during  the  1977  survey  and 
was  second  in  abundance  only  to  Q.  quadrula. 
Had  all  specimens  of  the  Asiatic  clam  been  col- 
lected, they  would  have  been  quantitatively  the 
most  significant  naiad  in  Lake  Springfield.  Lit- 
erally thousands  of  C.  manilensis  were  not  col- 
lected because  they  were  less  than  15  mm  in 
diameter.  In  fact,  the  lower  limit  of  15  mm  was 

established  after  the  first  station  was  visited  as 
the  task  of  collecting  all  Corbicula  was  found  to 
be  nearly  impossible  given  the  amount  of  time 
available  for  the  second  survey. 

Corbicula  manilensis  was  introduced  into  the 
fluvial  systems  of  North  America  as  late  as  1938 
and  has  since  spread  to  most  major  drainages  in 
the  United  States  (Sinclair  1971).  The  environ- 
mental conditions  this  freshwater  clam  is  able  to 
tolerate  in  Illinois  are  varied  but  as  late  as  the 
mid  1960s  it  was  not  found  in  the  Mississippi 
drainage  above  Carlo  in  Illinois  (Parmalee 
1967:95).  However,  over  the  past  ten  years  the 
species  has  become  established  in  the  Illinois 
River  (Thompson  and  Sparks  1977:34)  and  the 
major  reservoirs  of  the  Sangamon  River  drainage 
(e.g.  Lake  Springfield,  Lake  Decatur,  Sangchris 
Lake)  in  central  Illinois.  In  some  drainages  this 
species  has  been  found  to  exceed  269,000/M^  in 
density  and  in  instances  has  become  so  numerous 

FIG.  3.  Lake  Springfield,  Illinois,  at  Station  IS  (inlet)  during 
May.  19 77.  Water  level  is  at  normal  pool  (1 70. 69  m  MSL). 


October  30, 1979 

Vol.  94  (4) 

as  to  pose  problems  at  power  generating  and 
water  filteration  installations  (Sinclair  1971). 

Three  species  of  naiads  (i.e.  0.  reflexa.  C.  par- 
va,  and  T.  tntncataj  endemic  to  the  Mississippi 
River  drainage  have  also  become  established  in 
Lake  Springfield  since  the  initial  survey.  All 
three  species  were  known  to  exist  in  the  Sanga- 
mon River  drainage  at  the  time  of  the  1953 
survey.  0.  reflexa  and  T.  (nnicata  were  reported 
common  in  the  South  Fork  of  the  Sangamon  not 
far  from  the  lake,  and  an  abundant  population  of 
T.  tnmcata  and  C.  jxirm  was  noted  observed  in 
Lake  Decatur  (Parmalee  1955:31)  just  upstream 
from  Lake  Springfield  in  the  Sangamon  River.  It 
was  speculated  at  the  time  of  the  1953  survey 
that  these  species  were  either  not  present  in 
Sugar  Creek  prior  to  its  impoundment  or  that 
they  were  primarily  lotic  species  that  were  not 
able  to  adapt  to  the  man-made  lentic  habitat 
formed  by  Lake  Springfield. 

Results  of  our  1977  survey  clearly  demonstrate 
that  these  three,  especially  0.  reflexa.  are  capable 
of  maintaining  viable  populations  in  a  man-made 
reservoir  like  Lake  Springfield.  The  fact  that  over 
3300  M^  was  systematically  collected  at  20  dif- 
ferent loci  and  that  considerably  more  shoreline 
was  sporadically  surveyed  (but  not  collected)  and 
none  of  these  naiads  were  found  during  1953 
argues  strongly  for  a  more  recent  establishment 
of  the  species.  Live  specimens  of  0.  reflexa. 
utilized  in  another  study  (Parmalee  and  Klippel 
1974),  were  collected  at  Station  9  in  August  1971; 
several  individuals  were  between  five  and  six 
years  of  age,  which  indicates  this  species  had 
become  established  in  the  lake  at  least  by  1965— 
and  probably  earlier.  In  contrast,  C.  manilenms 
was  not  present  at  this  same  station  as  late  as 
spring  1973. 

The  means  by  which  these  mussels  could  have 
been  introduced  are  numerous,  but  two  of  the 
most  likely  avenues  known  to  us  are:  1)  their  in- 
troduction as  glochidia  with  fish  (primarily,  but 
not  exclusively,  white  bass)  obtained  from  other 
fluvial  systems  in  Illinois  and  placed  in  Lake 
Springfield  by  the  Illinois  Department  of  Conser- 
vation during  1951  and  1974,  or  2)  through  the 
emergency  water  supply  system  that  was  estab- 
li.shed  by  City  Water,  Light,  and  Power  shortly 
after  the  low  water  of  1953.  This  system  consists 
of  a  canal  that  was  excavated  from  a  dividing 

dam  along  the  east  shore  of  the  lake  to  nearby 
Horse  Creek.  Water  from  Horse  Creek  flows  in 
the  canal  to  the  dividing  dam  from  where  it  is 
pumped  into  the  lake.  According  to  City  Water, 
Light,  and  Power  records,  the  pumping  facility 
was  operated  for  a  short  period  after  its  comple- 
tion in  1956  and  again  during  1976  and  1977 
when  as  many  as  900  million  gallons  per  month 
were  pumped  from  the  canal  into  Lake  Spring- 
field. Either  small  fish  infested  with  glochidia 
and/or  glochidia  suspended  in  the  water  may 
have  been  carried  through  this  pumping  facility. 

Regardless  of  how  these  three  species  were  in- 
troduced they  all  seem  to  have  become  well 
established  and  are  fairly  widely  distributed.  (). 
reflexa  was  the  third  most  numerous  species 
recovered  during  the  1977  survey.  It  was  only 
outranked  in  frequency  by  Q.  qitadnda  and  C 
manilensw  and  was  nearly  as  ubiquitous  as  the 
first  and  second  ranked  species  (Table  1).  0. 
reflexa  is  noticeably  absent  and/or  in  low  fre- 
quencies along  the  upper  reaches  of  the  lake  and 
at  the  heads  of  inlets  (e.g.  Stations  13,  17,  18,  19, 
and  20).  In  general,  0.  reflexa  occurred  in 
greatest  frequencies  at  those  same  stations  where 
the  primary  species  were  found  in  increased  den- 
sity per  unit  area  during  1977  (e.g.  Stations  2,  5, 
9, 10,  and  12). 

C.  parva  and  T.  tntncata  were  the  eighth  and 
ninth  respective  most  numerous  of  the  13  species 
recovered.  C.  parva  was  found  at  and  near  rallec- 
tion  stations  throughout  the  lake  while  T.  trun- 
cata  in  sampling  strata  were  exclusively 
restricted  to  the  east  shore  of  the  main  body  of 
the  lake  (e.g.  Stations  2,  6,  7,  and  8).  At  least  20 
additional  T.  truncata  were  observed  outside  the 
sampling  loci  at  these  stations  but  in  only  one  in- 
stance was  the  species  observed  along  any  other 
portion  of  the  lake.  This  location  was  approx- 
imately 90  meters  outside  the  area  collected  at 
Station  5  which  is  also  along  the  lower  portion  of 
the  main  body  of  Lake  Springfield  but  on  the 
west  shore.  Whether  the  present  low  population 
number  is  a  result  of  what  appears  to  be  a  fairly 
recent  introduction  (the  largest  individuals  are 
ca.  4-5  years  of  age)  or  the  inability  of  a  typical 
river  species  to  adapt  to  a  lake  environment  is 
not  clearly  understood. 

Vol.94  (4) 

October  30, 1979 


Comparisons  and  Discussion 

Few  thorough  studies  of  quantitative  and 
qualitative  changes  in  naiad  fauna  resulting  from 
artificial  impoundment  of  fluvial  systems  and 
subsequent  adaptation  to  lentic  environment  have 
been  reported  for  North  America.  The  pelecypod 
fauna  from  Lake  Texoma  in  Texas  and  Oklahoma 
have  been  studied  and  reported  (Riggs  and  Webb 
1965;  White  and  White  1977)  and  some  work  had 
been  conducted  in  the  Red  River  prior  to  its  im- 
poundment (Isely  1925).  Conclusions  set  forth  on 
the  basis  of  the  most  recent  studied  suggests  that 
"despite  the  many  conditions  seemingly  working 
against  the  pelecypods  of  Lake  Texoma,  it  can  be 
said  with  some  degree  of  confidence  that  they  are 
flourishing  when  compared  to  their  original  di- 
versity and  abundance"  (White  and  White  1977: 

Unfortunately  quantitative  data  are  not  avail- 
able to  measure  the  strength  of  this  observation. 
Variations  in  survey  strategies  preclude  the  pos- 
sibility of  making  direct  comparisons  from  one 
report  to  the  next.  White  and  White  (1977:248) 
note,  for  example,  that  "Tlie  .study  by  Riggs  and 
Webb  (1956)  found  that  the  mussel  populations 
of  the  lake  were  much  more  established  than  had 
been  indicated  previously;  however,  since  they 
surveyed  only  one  of  the  possible  lake  habitats,  a 
loamy-sand  substrate,  the  data  could  not  be  used 
to  draw  conclusions  about  the  abundance  of  spe- 
cies throughout  the  entire  lake."  In  fact  Riggs 
and  Webb  (1956:200)  report  information  that  in- 
dicate the  average  naiad  density  was  .39/m^  dur- 
ing 1953  while  information  provided  for  more 
varied  habitats  by  White  and  White  (1977:242) 
show  that  the  mean  density  was  .12/m^  during 
1975-1976.  Only  two  of  the  stations  collected  by 
White  and  White  (1977-stations  7  and  9)  pro- 
duced as  high  a  density  (>  .24/m^)  as  the  station 
producing  the  lowest  density  during  1953  (Station 
8)  when  a  portion  of  the  lake  was  collected  by 
Riggs  and  Webb  (1956).  The  1975-1976  collections 
did  produce  three  species  not  collected  by  Riggs 
and  Webb  (1956),  i.e.  L.  complanata,  0.  refleoca 
and  LampsiiLs  teres.  However,  the  significance  of 
this  observation  is  also  rendered  less  impressive 
when  one  considers  that  White  and  White  (1977) 
collected  a  surface  area  of  over  seven  times  as 
great  as  the  area  collected  during  1953. 

Unlike  the  claims  made  for  Lake  Texoma,  most 
observations  made  on  naiads  in  the  impound- 
ments of  the  larger,  previously  swift,  streams  and 
rivers  of  southeastern  United  States  indicate  that 
mussel  populations  have  been  drastically  altered 
(e.g.  Bates  1966;  Stansbery  1964;  Isom  1969). 
Bates  (1966:235)  notes,  for  example,  that  "Most  of 
the  large  river  forms  which  were  characteristic  of 
the  pre-impoundment  assemblage  [in  the  Ten- 
nessee River]  are  now  typically  absent  from  these 
shallow  water  habitats"  in  the  Kentucky  Reser- 
voir. "The  one  exception  noted  here  is  Q. 
quadnda,  which  has  successfully  invaded  these 
areas.  Many  juveniles  of  this  species  were  col- 
lected from  both  the  beach  areas  and  the  mud 
shallows  indicating  a  much  higher  biotic  poten- 
tial for  this  species  than  for  the  other  Union- 
inae."  In  addition  to  Q.  quadrida  and  C.  parva, 
various  species  of  Leptodea  and  Anodonta  com- 
prised the  dominant  naiads  recovered  by  Bates 

Pronounced  changes  in  mussel  population  of 
unimpounded  fluvial  systems  have  also  been  well 
documented.  In  many  of  the  streams  of  the  Mid- 
west the  overriding  observation  is  that  popula- 
tions have  undergone  various  degrees  of  degradia- 
tion  (e.g.  Clark  1976;  Matteson  and  Dexter  1966; 
Starrett  1971).  One  point  of  interest  here  is  that 
all  three  of  these  reports  on  mussels  in  streams 
flowing  through  or  bordering  Illinois  note  the 
hardiness  of  Quadrida  qimdnda  despite  siltation 
and  pollution  (Clark  1976:8;  Matteson  and  Dexter 
1966:99;  Starrett  1971:363).  Also  of  interest  is 
Clark's  (1976:8)  notation  of  recent  increases  in  the 
occurrence  of  0.  reflexa  in  the  Wabash  River. 

A  survey  of  pre-impoundment  Lick  and  Sugar 
creeks  in  central  Illinois  was  never  undertaken. 
Consequently  it  is  impossible  to  compare  or  con- 
trast species  of  the  original  lotic  environment 
with  those  in  the  subsequent  artificially  produced 
lentic  environment  resulting  from  the  construc- 
tion of  Lake  Springfield.  However,  mussel  popula- 
tions of  the  lake  were  surveyed  (1953)  nearly  two 
decades  after  impoundment  (1935).  Slightly  over 
two  decades  later  (1977)  a  survey  of  the  same  loci 
collected  during  1953  was  again  undertaken.  Re- 
sults of  this  second  survey  conclusively  demon- 
strate that  naiad  density  per  unit  area  has  gen- 
erally increased  and  that  species  diversity  has 


October  30, 1979 

Vol.94  (4) 

also  taken  place  in  Lake  Springfield.  In  this 
respect  the  results  of  this  second  survey  are 
similar  to  the  claim  for  Lake  Texoma,  i.e.  "in- 
creasing density  and  diversity  within  the  lake" 
(White  and  White  1977:235). 

Seven  of  the  ten  species  reported  for  Lake  Tex- 
oma occur  in  Lake  Springfield  and  seven  of  the 
12  species  recovered  from  Lake  Springfield  are 
also  found  in  Lake  Texoma.  Riggs  and  Webb 
(1956:201)  report  L.  laevissirym  and  Q.  qmidnda 
as  the  first  and  second  respective  most  common 
species  in  Lake  Te.xoma  while  White  and  White 
(1977:242)  report  L.  laeinssima  and  A.  yrandis  as 
the  two  most  numerous  species.  In  the  Lake 
Springfield  populations  for  both  1953  and  1977,  Q. 
quadrula  was  most  numerous  and  L.  laenssima 
the  second  most  common  of  the  Unionacea.  Also, 
as  in  the  case  of  Lake  Springfield,  0.  reflexa  is  a 
recent  addition  to  Lake  Te.xoma  as  it  was  not 
recovered  by  Riggs  and  Webb  (1956)  in  1953. 

While  Q.  fjuadritla  has  seemingly  decreased  in 
Lake  Te.xoma,  the  species  has  actually  increased 
in  frequency  in  Lake  Springfield.  This  seems  to 
conform  to  some  findings  in  both  streams  and 
rivers  of  the  Midwest  (Matteson  and  De.xter  1966) 
and  lake  environments  in  the  South  (Bates  1962). 
The  manner  in  which  Lake  Springfield  does  not 
appear  to  compare  favorably  with  many  other 
reported  populations  in  the  Midwest  and  South- 
east is  that  there  does  not  seem  to  be  an  overall 
degradation  of  naiad  populations.  Degradation  of 
the  population  seems  to  be  occurring  in  the  upper 
reaches  of  Lake  Springfield,  as  well  as  at  the 
heads  of  inlets,  but  populations  in  the  main  body 
of  the  lake  generally  have  thrived  over  the  past 
two  decades.  However,  as  Lake  Springfield  con- 
tinues to  silt  in,  it  is  expected  that  the  naiad  den- 
sity per  unit  area  will  continue  to  decrease  and 
that  A.  (jrandis,  A.  imbecilis,  and  L.  laevmima 
will  continue  to  increase  in  relation  to  other 
species  in  the  agrading  portions  of  the  lake. 

Hinge  Anomalies 

Anomalies  occurring  in  the  form  of  transposed 
lateral  hinge  teeth  have  been  noted  in  freshwater 
bivalves  for  over  a  centur\'  (Agassiz  18.59:  I^ea 
1860).  Van  der  Schalie  (1936)  revised  Lea's  1860 
list  and  included  his  own  records  of  species  ex- 
hibiting various  combinations  of  transposed  teeth 

which  he  accumulated  during  many  years  of  in- 
tensive collecting.  In  addition  to  the  eight  species 
recorded  by  Lea,  van  der  Schalie  listed  18  others 
which  represented  (for  all  species)  72  anomalous 
individuals.  None  of  the  hinge  variations  de- 
scribed by  these  workers  were  found  in  species 
belonging  to  the  genus  Qiiadiida,  so  the  oc- 
currence of  transposed  teeth  in  13  individuals 
from  the  1977  sample  of  Q.  quadnda  collected  in 
Lake  Springfield  is  worthy  of  note. 

The  normal  dentition  in  species  belonging  to 
the  family  Unionidae  consists  of  double  lateral 
and  pseudocardinal  teeth  in  the  left  valve  and  a 
single  lateral  and  pseudocardinal  tooth  in  the 
right.  At  least  five  distinct  variations  were 
observed  among  the  13  anomalous  individuals: 
single  lateral  in  each  valve  (N  =  3):  double 
lateral  in  both  valves  (N=3):  single  lateral  in 
left,  double  in  right  (N  =  4):  double  lateral  in  left 
valve,  partly  treble  in  right  (N  =  2);  treble 
laterals  in  both  valves  (N  =  l).  One  of  the  in- 
dividuals possessing  a  single  lateral  in  the  left 
valve  and  double  lateral  in  the  right  is  addi- 
tionally noteworthy  because  the  i3seudocardinal 
teeth  are  also  transposed.  Whether  or  not  re- 
versed or  transposed  hinge  teeth  in  freshwater 
bivalves  are  a  result  of  environmental  or  genetic 
factors  is  not  clearly  understood.  However,  the 
fact  that  such  variations  in  hinge  structure  do  oc- 
cur, even  if  uncommonly  to  rarely,  is  significant 
in  relation  to  their  use  as  characters  in  iden- 
tification and  classification.  Transposed  hinge 
teeth  were  not  noted  in  individuals  of  the  other 
species  from  Lake  Springfield.  The  anomalous 
specimens  of  Q.  quadnda  comprised  approximate- 
ly one  percent  of  the  sample  of  that  species. 


Systematic  surveys  of  the  naiad  fauna  in  the 
artificially  formed  lentic  environment  of  bike 
Springfield  of  central  Illinois  were  undertaken 
during  1953  and  1977.  Comparable  survey  strat- 
egies employed  during  both  sun'eys  has  made  it 
possible  to  make  direct  comparisons  of  the  naiad 
populations  over  a  period  of  a  quarter  of  a  cen- 

Both  quantitative  and  qualitative  changes  have 
occurred  in  the  naiad  fauna.  Generally,  the  naiad 
density   per  unit  area  h;is  increased  along  the 

Vol.94  (4) 

October  30, 1979 


shores  of  the  main  bt)dy  of  the  lake  while  the 
density  in  the  upper  reaches  of  the  lake  and  at 
the  heads  of  the  inlets  has  decreased.  Com- 
mencerate  with  the  decreased  density  that  has  oc- 
curred in  these  portions  of  the  lake  that  have 
been  agrading  over  the  past  25  years  are  the 
changes  in  relative  proportions  of  certain  species 
of  mussels;  L.  laevissima.  A.  grandis.  and  .4.  ///;- 
bcciliti  have  increased  with  respect  to  other  species 
in  these  habitats. 

Qualitative  changes  in  the  mussel  fauna  have 
also  taken  place  in  Lake  Springfield.  All  of  the 
species  recovered  during  1953  were  also  recorded 
during  1977.  In  addition,  four  species  (i.e.  C.  par- 
va.  T.  truncata.  0.  reflexa.  and  C.  manilensw) 
have  become  newly  established  in  the  lake.  Depo- 
sition of  silt  in  the  areas  of  entry  of  the  feeder 
creeks  appears  to  greatly  inhibit  the  establish- 
ment and  growth  of  naiads.  With  continued 
heavy  silting  at  several  locales  in  the  lake,  ac- 
cidental introduction  or  periodic  stocking  of  fish, 
and  with  possible  unforeseen  changes  in  the  pre- 
sent lake  habitat,  a  future  study  of  the  mussels  of 
Lake  Springfield  may  well  provide  additional 
useful  data  relative  to  population  dynamics 
under  artificial  conditions. 


We  would  like  to  thank  Arthur  E.  Bogan, 
Department  of  Anthropology,  University  of  Ten- 
nessee, Knoxville,  for  his  assistance  with  the  in- 
itial sorting  and  processing  of  the  Lake  Spring- 
field naiads.  James  R.  Purdue,  Illinois  State 
Museum,  Springfield,  furnished  the  photograph  in 
figure  2b  and  Marl  in  Roos,  Illinois  State 
Museum,  Springfield,  provided  prints  of  all  of  the 


Agassiz.  Louis.  1859.  Notes  on  Unio  ligamentimts  reversed. 

P)vc.  Boston  Sue.  Nat.  Hisl.  7:166-167. 
Bates.  John  M.   1962.  The  impact  of  impoundment  on  the 

masse!    fauna    of    Kentucky    reservoir.   Tennessee    River. 

Amrr  Midi  Nat.  m:2»>--m. 
Clark,  Clarence  F.  1976.  The  freshwater  naiads  of  the  lower 

Wabash  River.  Mt.  Carmel.  Illinois  to  the  south.  Sterkiana 

Isely.  F.  B.  1925.  The  fresh-water  mussel  fauna  of  eastern 

Oklahoma.  Proc.  Okla.  Acad.  Sri.  4:43-118. 
Isom,  B.  G.  1969.  The  mussel  resource  of  the  Tennessee  River. 

Malacoloyia  7:397-425. 
Lea.  Isaac.  1860.  Proceedings  of  Acad.  Nat.  Sri,.  Phil.  51-.53. 
Matteson.  Max  R.  and  Ralph  W.  Dexter.  1966.  Changes  in 

Pelecypod  populations  in  Salt  Fork  of  Big  Vermilion  River, 

Illinois  1918-1962.  The  Nautilus  79:96-101. 
Parmalee.  Paul  W.  19.55.  .Some  ecological  aspects  of  the  naiad 

fauna  of  Lake  Springfield,  Illinois.  The  Nautibi.^  69:28-.34. 
.  1967.  The  fresh -water  mussels  of  Illinois.  III.  St. 

Mj«.  Pop.  Sri.  Sw.  8:1-108. 
and  Walter  E.  Klippel.  1974.  Freshwater  mussels 

as  a  prehistoric  food  resource. .4mer.  Antiq.  39:421-434. 
Riggs.  C.  D.  and  G.  R.  Webb.  19.56.  The  mussel  population  of 

an  area  of  loamy-sand  bottom  of  Lake  Texoma.  ,4  me?-.  Midi. 

AVir.  56:197-203. 
Sinclair,  R.  M.  1971.  Annotated  bibliography  on  the  exotic 

bivalve  dirbicula  in  North  America,  1900-1971.  Sterkiana 

Stansbery,  D.  H.  1964.  The  Mussel  (Muscle)  Shoals  of  the  Ten- 
nessee River  revisited.  Ann.  Report  Amer.  Malacol.  Union. 

Starret,  William  C.  1971.  A  survey  of  the  mussels  (Unionacea) 

of  the  Illinois  River:  a  polluted  stream.  HI.  Nat.  Ifist,  Surv. 

Bull.  30:266-403. 
Thompson,  Carl  M.  and  Richard  E.  Sparks.  1977.  The  Asiatic 

Clam,    Corbiculo    manilenfds    in    the    Illinois    River.    The 

Nautilus  91:31-36. 
van  der  Schalie,  Henrv-.  1936.  Transposed  hinge  teeth  of  North 

American  naiades.  The  Nautilus  49:79-84. 
White.  David  S.  and  Susan  J.  White.  1977.  Obser\-ations  on 

the  pelecvTxid  fauna  of  Lake  Texoma,  Texas  and  Oklahoma, 

after  more  than  30  years  impoundment.  Southwest.  Nat. 






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will  hold  2,000  pages  and  has  colorful,  easy-to- 
read  guide  tabs  for  the  maior  sections  Sup- 
plements and  price  changes  can  be  quickly  ad- 
ded Other  journals  such  as  Indo-PaQlUc 
Mollusca  and  Hawaiian  Shell  News  will  fit  into 
this  binder  Eilra  binders  available.  ($  8-95) 

been  assembled  from  the  latest  scientific 
publications  of  such  eminent  malacologists  as 
Abbott,  Cernohosky,  Rehder,  Rosewaler,  Emer- 
som.  Clench,  Powell,  Ponder  and  many  others 
Formerly  called  Van  Nostrand's  Standard 
Catalog  of  Shells  Now  published  by  American 
Ma/aco/og/s(s,  Publishers. 

Destined  to  be  a  complete  technical  listing  of  all 
the  living  marine  shells  of  the  world  The  Stan 
UAKU  Catalog  also  gives  the  current  market 
values  of  the  better-known  species  ISBN-  O-915826-03-8 

Llnder  the  editorship  of  Robert  I    L   Wagner  and 
R     Tucker  Abbott,   this  monumental  work   has 

GEOGRAPHICAL  (Vols.  1-90)  AND  SCIENTIFIC  NAMES  (Vol.  61-90) 

A  Vital  Key  to  a  Major  Source  of  Original  Research  on  Mollusca 

1.  New  Index  to  all  the  Scientific  Namei^  appearing  in 

volumes  61  through  90  (1947-1976).  Contains 
31,400  page-references  to  1.5,000  names.  Cross  in- 
dexed on  the  species-genus  level.  Covers  30  years. 

2.  (jCdgmphwal    Index    to     volumes     1     through     90 

(1886-1976).  90  years  of  American  and  foreign 
malacological  research  at  your  finger  tips.  The  full 
titles  of  .5,200  articles  are  arranged  geographically 
and  chronologicaly  into  50  U.  S.  states  and  15  ma- 
jor foreign  areas.  Further  divided  into  marine, 
land  freshwater  and  fossil  subjects. 

3.  Antlmr  Index  to  The  Nautilus,  volumes  1  through 
75.  (gives  full  titles,  date,  volume  and  page 
reference;  Anonymous  and  Obituaries  listed 
separately).  Prepared  by  Aurele  La  Rocque. 
Published  1963.  We  have  acquired  the  last  1-50 
copies  that  were  printed  ,  and  have  had  them 
bound.  Obviously,  this  will  soon  be  out-of-print 
and  unavailable.  Is  your  old  one  dogeared?  279  pp., 
paperbound.  (postage  paid)  $8.00. 

Even  if  you  don't  own  a  complete  set  of  THE  NAUTILUS. 
these  inde.xes  will  quickly  tell  you  what  volumes  to  borrow  on 
interlibrary  loan  or  what  pages  to  have  reproduced  for  your 
special  research  project.  No  one  dares  make  a  sun'ey  or  des- 
cribe a  new  speices  without  consulting  this  valuable  tool. 

Both  in  one  clothhiund  volume.  8  x  10  ' :  inches,  2.50  pp.  $24.00  (postage  paid). 


(KP'o  discount  on  two  or  more  copies  on  same  order). 

ORDER  l^OW:  American  Malacologifsts.  Inc.,  Box  22,55,  Melbourne,  FL  32901 


The  annual  subscription  rate  for  The  Nautilus 
is  $10.00  for  individuals  (foreign  $11.00)  and  $15.00 
for  institutions  (domestic  or  foreign).  Subscrip- 
tions may  begin  in  January.  Send  check  or  money 
order  made  out  to  "American  Malacologists"  to 
the  Business  Manager,  P.O.  Box  2255,  Melbourne, 
Florida  32901,  U.S.A. 

Back  issues  from  volume  72  to  date  are  ob- 
tainable from  the  Business  Manager.  Volumes  1 
through  71  (if  available)  may  be  obtained  in 
reprint  or  original  form  from  Kraus  Reprint 
Co.,  Route  100,  Millwood,  New  York  10546. 
Advertising  rates  may  be  obtained  from  the 
Business  Manager  or  Editor. 


Mamtscripts:  Authors  are  requested  to  follow 
the  recommendations  of  the  Style  Manual  for 
Biological  Journals,  which  may  be  purchased 
from  the  American  Institute  of  Biological  Sci- 
ences, 1401  Wilson  Boulevard,  Arlington,  Va. 
22209.  Manuscripts  should  be  typewritten  and 
doublespaced ;  original  and  one  copy  are 
required,  to  facilitate  reviews.  Tables,  numbered 
in  arable,  should  be  on  separate  pages,  with  the 
title  at  the  top.  Legends  to  photographs  should 
be  typed  on  separate  sheets.  Explanatory  terms 
and  symbols  within  a  drawing  should  be  neatly 
printed,  or  they  may  be  pencilled  in  on  a  trans- 

lucent overlay,  so  that  the  printer  may  set 
them  in  8  pt.  type.  There  is  a  charge  of  50  cents 
per  word  for  this  extra  service.  All  authors 
or  their  institutions  will  be  charge  50  cents 
per  line  of  tabular  material  and  taxonomic 
keys.  The  publishers  reserve  the  right,  seldom 
exercised,  to  charge  $40  per  printed  page. 

An  abstract  should  accompany  each  paper. 

Reprints  are  available  at  cost  to  authors.  When 
proof  is  returned  to  authors,  information  about 
ordering  reprints  will  be  given.  They  are  obtained 
fi-om  Economy  Printing  Co.,  Inc.,  R.D.  3,  Box  169, 
Easton,  Maryland  21601. 


It  is  becoming  increasingly  important  for 
future  research  purposes  that  an  identified  sam- 
pling of  species  mentioned  in  publications  be 
deposited  in  a  permanent,  accessible  museum 
specializing  in  mollusks.  This  is  particularly 
true  of  mollusks  used  in  physiological,  medical, 
parasitological,  ecological,  and  experimental 

Several  museums  of  natural  history  have  ex- 
tensive modern  facilities  and  equipment  for  the 
housing  and  curating  of  voucher  specimens. 
Material  should  be  accompanied  by  the  identifica- 
tion, locality  data  and  its  bibliographic  reference. 
There  is  no  charge  for  this  permanent  curating 
service,  and  catalog  numbers,  if  desired,  will  be 
sent  to  authors  prior  to  publication. 

Will  pay  good  prices  for  libraries,  second- 
hand books  and  reprints  on  mollusks,  shells 
and  conchology.  Back  numbers  of  The  Nauti- 
lus, vols.  40-71  wanted,  $1.50  each.  Phone  (1- 

305-725-2260)  or  write:  R.  Tucker  Abbott, 
Americnn  Malacologists.  Inc..  P.  0.  Box  2255 
Melbourne,  FL  32901.  Free  appraisals. 


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